Another option you might consider is getting one of the new tube preamps from Schiit Audio, like the Frea, then pairing it with a brute SS amp like a used Sunfire. You'd come in at around the same $$$ as a new Sphinx but with more power.
I'm a fan of Maggies, but for a room that size, I highly recommend considering some nice 2-way monitors. You'd be surprised how good a soundstage such speakers can create in a small room. Kef LS50s or some Ascend Acoustics Sierras should work well in room that size.
I'm a fan of Maggies, but for a room that size, I highly recommend considering some nice 2-way monitors. You'd be surprised how good a soundstage such speakers can create in a small room. Kef LS50s or some Ascend Acoustics Sierras should work well in room that size.