Here are the basic details:

1. Two 15 open baffle woofers mounted on a large damped, dead and braced open baffle. 

2. Two midrange drivers in d'apollito configuration on another dead , damped and braced open baffle with a Beryllium or AMT tweeter in between.  The tweeter set back for time alignment and with plenty of felt around all three drivers.  If you are using a forward firing driver then another tweeter can be mounted on rear to give some dipole coverage of highs.  A dipole AMT like the ESS will not need a rear tweeter.

3. A three channel amp would sit right behind each channels baffles and tri-amp the system.  The speaker wires would be hardwired directly from the amp to the xover parts or directly to the midrange drivers.

Here are more specifics:

The two woofers would be the Acoustic Elegance Dipole 15 woofers.....these things are incredible.  The xover for these woofs would be 12 gauge Jantzen toroidal core coils or 10 gauge foil coil ferrite core from Mundorf and super caps.  These two inductors have the lowest impedance and therefore give the woofers the best control.  The xover parts would be damped on a separate isolated stand behind the woofer panel.  The wires from the coil would be soldered using super wire directly to the voice coil wires on each speaker.....the two drivers would be wired in parallel to give a 4 ohm load at around 93db sensitivity.....so 500 watts into 4 ohms will play at least 110db. The woofer panels would be moved relative to the mid/high panel so they would give perfect time alignment at your seating position......set by ear and measurement.

The panels would be made from three layers of three quarter inch material.....alternating between birch plywood, bamboo plywood and highly refined MDF.  Wings on the backside would double as braces.  You would not need wings for the mid/high panel but you do want it braced.  You could also use green glue in between layers for even more damping.  Massive stands and bracing would go up most of the way on the back of each panel.  They would be super dead.

The amps would be VTV large chassis three channel Purifi amps using two 1200 watt power supplies.  There are new Purifi higher powered modules about to go on sale and these sound better, even when using low power.  One power supply would be for the woofer amp and the other would run the mid and high amps.  These two three channel amps would be modified by me using air core coils on the output of the mid and high units.....and all the other mods I do.  The speaker wire is hardwired directly inside the amp.  You could also use one NC1200 in place of a Purifi module for even more bass power.

The speaker wire would be custom cryoed 14 guage PCOCC Neotech litz wire for the mids and highs and Furutech cryoed 11 gauge wire for the woofers.  There would be no spades or any connectors as all wires are soldered everywhere.  The wire would be tried in both directions to see whch direction sounds best.  All wires would be suspended from the floor.

Ground Enhancers would be mounted directly to to the ground terminal of each driver. Bybee Quantum Clarifiers would be placed on the back of each midrange and woofer (8 total).

Here are some links to the drivers and parts:

http://aespeakers.com/shop/dipole/dipole15

You would get the two 16 ohm tap verson and wire them in parallel and then both drivers in parallel to get a four ohm load

https://purifi-audio.com/transducers/ptt6-5w08/

The drivers would be wired in parallel to ge a four ohm load......this is not the driver you want, please see the Purifi site for the new dedicated midrange driver.

http://www.bliesma.de/Datasheet T34B-4.pdf

You could use a much cheaper tweater on the rear for rear high frequency addition....but for best sound and matching sensitivity I would use the same tweeter on the rear (you can alwasy pad down the rear tweeter to taste and room).

https://vtvamplifier.com/product/vtv-amplifier-three-channel-purifi-audio-1et400a-amplifier/

The above link is for a three channel amp with a 3000 watt supply......what you really want is two 1200 watt supplies. Warren at VTV can do this for you.....no problem......and you want the new not yet released modules from Purifi.  I will update this info when the new Purifi amps and Purifi drivers are available to purchase.

https://www.youtube.com/watch?v=WBXXDuTn6sM

The above video shows  two 12 inch Acoustic Elegance open baffle drivers used on a 3 way tri-amped speaker.  One could make a similar thing using 2 mids and have it look fantastic and sound incredible.  However, you really want to time align the mids and tweets to the woofers.....in this case it was done digitally in the digital xover.  If you had to do it mechanically then you would want the mids and tweets stepped back on the bafflee.....very complex thing to do.  This is why I prefer to have the bass on a separate panel......you can time align easily and there is less interaction betwen the bass and mid/highs.  Plus it allows you to make new baffles for either different mids/highs or woofs without messing with the entire design.

Here is a basic parts list and approximate costs:

4  Acoustic Elegance Dipole 15 woofers   $2000
4  Purifi 6.5 inch 8 ohm drivers for the mids  $1600
4  Bleisma tweeters.....two for front and 2 for rear  $1600  or two ESS AMT tweeters for $400
2  Three channel VTV 3 channel amps with two 1200 watt power supplies  $6000
Both amps modified by me.  $3000?
Wood for baffles (bamboo plywood, Birch plywood and highly refined MDF  $1000
felt for around the tweeters and mids  $100
2 16 gauge foil coils for tweeter  $100
2 Clarity Cap MR caps for tweeter  $150
4 copper foil bypass caps for tweeters and bass  $140
2 Jantzen toroidal core coils for woofers  $300
2 large Clarity Cap MRs for woofers  $300
15 feet 14gauge PCOCC Neotech Litz wire  $150
30 feet 11 gauge Furutech wire for woofers.   $150
2 inner tubes for isolating the amps from floor.....you could use springs, as well  $40
2 Ikea Bamboo cutting boards as amp shelves  $70
2 1.5 inch thick maple shelves as amp shelves (you stack the bamboo on the inner tube, then the banboo shelf 
and then the Maple shelf on top   $200
2 sets Mad Scientist best footers for under each amp.  $600
3 pairs ground enhancers.....mounted directly on drivers  $80
8 Bybee Quantum Clairifiers  $800
Misc. hardware.....brass screws for drivers, etc.  $100
2 Power cord for amps......$500 for both made with Furutech or VH wire and copper plugs.
Finishing speakers (paint, veneer, nothing, whatever)????  Nothing to lots....especially if you are having someone else make of finish the speakers.

About $19K plus finishing.  You could substitute less expensive woofer, midranges, tweeters without much lose of quality. 

1.  The Wilson speaker has 4 sets of binding posts in series with the mids and highs.....one set in series with the woofers.  It also has one set of speaker spades in series with the mids and highs.  All connectors veil the sound.

2. It uses Caddock power resistors to pad the mids and highs.  There is no perfect resistor but I have found that bypassing a power Caddock resistor with a Nude Vishay resistor is way more transparent.

3. The midrange and woofers are most likely wired to the posts or tabs on the drivers.  I have never seen a manufacturer solder the wires from the xover directly to the voice coil wire.  Bypassing the speaker connector gives more information.  Less is more.

4. The midrange drivers are in a box......therefore limiting the openess they can give.  The midrange drivers have speaker level xover parts......using a line level xover using nude Vishy resistors and copper foil poly caps is way more transparent.....plus you need no veiled large power resistors.

Certainly the Wilsons will have great bass....and maybe more than the above speaker......however, you could use 4 15 inch woofers per side and blow your brains out.   However, a major problem with the Wilsons is there low impdance.  You really need super high current amplification to drive them to the max....so, you then you have to buy an expensive monster amp to drive them.  If you design a speaker with reasonable impedance than you have lots more possiblilies of amps to use and for way less money.