Quick response! I edited and you posted before I got done. OK, I thought you bought full kits and the flat packs from the captain.
There are many ways to execute this design, my plan at present is to build a set of the subs driven by the A370PEQ amps as standalone subs to play with in my HT and main stereo. Then, as opportunity allows, work up a set of vertical arrays similar to HAL's Monolith design. I have 8 Neo8's and 8 Neo3's from the pre Christie Digital/BG era and I have access to machining and so can have a solid metal frame fabricated which I want to then sandwich with materials to damp vibrations. I envision the front of the baffle covered with wood that can have waveguides routed in. Yes, this will be dipole and yes, I have a lot to learn still. Fortunately there are plenty of resources.
My dream speaker project that is obviously based on other's work but intrigues me enough to pursue it.
Sorry for going a bit OT, now back to our regularly scheduled thread, 
It's pretty seamless actually we can supply you with the flat packs (either modular or non-modular) that match up perfectly with Danny's electronics. You'll get everything you need to compete the build. If you prefer, completed cabinets also are an option but shipping costs increase due to size/volume.
Our modular subs are easily upgradable if you start with duals. Going to triples, quads , or even 6 stacks is pretty straight forward (quads and 6 stacks will need a change from the A370 PEQ to the HX800).. If you anticipate a possible upgrade from the duals, be sure you start with the SW12 16FR woofer, the Sw12 08FR won't work for triples or 6 stacks .... gets a little confusing as you could actually go from duals to quads using the SW12 08FR's, but triples or 6 stacks require the 16's due to impedence load.
Making a speaker with Neo3/Neo8's is not going to work, they cover similar ranges (the Neo 8 a bit lower) but neither will reach low enough , even in a wave guide, to cross to the OB subs. Additionally, if you are only using 4 Neo 3's per speakaer in a line, you are going to run into serious filtering issues, you'd be better off using a single Neo3 or going to say 9 (minimum or 16 (preferable).
The Neo 3/Neo10 is going to be a far better match, how you lay them out and implement them will be a huge factor in how successful you end up being with this.... there's a lot going on here, it can take some time to get a hndle on it, and even when you think you 've got it, you may not... trust me

But, you're in the right place , lots of great info here and Danny is always willing to help
jay