The challenge is to make a speaker as good as or better than a Wilson or Magico for less than a fraction of the money. The best drivers can still be plenty expensive. I liked the comment above about making plate speakers and wholeheartedly agree. No enclosure is better than any enclosure. Simple is always best. I made a system for a friend who has muscular dystrophy using Focal drivers back when they still sold them to the public. They used plates of laminated MDF and solid surface material. No painting required. Focal had a midrange/upper bass 6" driver that made it nicely down to 150 Hz allowing me to jump down to subwoofers. They were two way and used a very simple 2nd order crossover. I still get comments about the system 20 years later.
Just pick your drivers carefully Don't worry about sensitivity. Initially wire the drivers with Pots and adjust them till you get what you want then read the resistance off the pot and get good resistors the same value. Just be careful how this interacts with the crossover. There is a bit of trial end error here.