I have been getting enthusiastic emails from a reviewer for one of the major e-mags to whom I sent a pair of stock RM 30C and a powered Larger Sub. He reports this combo fills his high-ceiling 17x30' room well and the single Sub shakes the walls.
Duh! Two 15s, a 12, 5 cu ft & 1000WRMS may do that...

I think your best choice is the 30C with the OXO, add the sub later when budget permits. The OXO makes upgrades easy at a later date, and stock cabinets (lite and dark oak, mls satin black) keep the price under $4k delivered.
Dittos!