M3s all round is an option. I think they will play almost as loudly as M22s.

Hsu STF-2 might be an option if you're on a tight budget, but I'm guessing the EP350 would outperform it in a large room.

M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8