Knowing that you may want better highs eventually, you might consider building it with a 35 inch slot for 30 Dayton Neo 20FA's per side. You can get them for about $3.50 each if you order 60 of them at once. You have to ask though. Then when you want to add crossovers and better highs, you're almost ready to go.

When i bought my Sammi's(3.5 inchers) two years ago, i bought just one, and compared it to my then current system. That consisted of a 1.25 inch audax soft dome tweeter, a Vifa BC-14SG49, and a Goldsound(not goldwood) 12 inch 15 mm x-max woofer. I took the woofer out of the circuit, and put the Sammi in a PVC tube . Without the woofer, the sammi was clearly more detailed than the vifa/audax combination on acoutic guitar. Of course when the volume needed to be turned up it lost, or the music got more complex. And when I connected the woofer and played it, anything with bass below 80hz made the Sammi lose. But i suspect that with 34 of them the story would have been different.

Marlboro