I've been impressed with Monoprice's line of speakers. Their Monolith line is outside your budget, but you may want to give their MP-65 line a look.
MP-T65RT Towers - $119.99 ea.
MP-C65RT Center - $59.99
MP-65RT Bookshelf - $64.99/pair
SW-12 12" 400-watt subwoofer - $229.99 or SW-10 10"...