Should I buy PSB Image T6's for $800?

They are 91db. You should only need 20 watts to power them. There is a review at Soundstage. Never heard them, but they should be a match with your amp.

good speaker--no real flaws. quite efficient, so your nova should drive 'em fine, and i'd expect it'll be a definite upgrade for you. msrp is $1199; i see 'em advertised new for $999, so $800 used registers as neither a great bargain nor a terrible deal. at around the same range you might also consider energy veritas or revel f12, both also very good.

Someone else told me I should be looking at speakers with 98db efficiency and the Nova wouldnt be good enough. Does that make any sense?