Nice design, but the best/most efficient bass reproduction comes from distributed bass (read Floyd Toole's "Sound Reproduction") so I'd vote for a 2-way stand mount with 4 DSP'd subs.
In light of this thread being a first for the OP and a wonderful and elegant design well executed, I don't see the relevance of your uninvited vote. Support and encouragement is such a nice gift to new ideas.
Beautiful skills by the way, and more pics please. I see many DIY designs but few as pretty as this one.