No, I don't build the driver, altho someday maybe, who knows? I built one of the
Dayton BR-1 kits, and that came with a pre-built box but I assembled the crossover and installed the drivers, ports and terminal. I'm building essentially another of these but building my own box/baffles this time and using Dennis Murphy's crossovers that he made for the speakers; he offers a pre-built speaker with his crossover for not much more than the price of the kit, so unless you really want to put something together, I can very much recommend his Affordable Accuracy speakers
http://philharmonicaudio.com/aa.html
Designing a speaker from the ground up, choosing the drivers, determining the best crossover design, the best box etc is a lot of time/work....may as well take advantage of designs/kits available for proven designs.