What brand and model are your speakers? If they're as good as your pre and amp they would do fine for your right and left if you go 5.1|7.1 provided you can get complimentary center and surrounds. As for your pre and pro you could use them as the basis for a component system and add matching pre-amps, amps and sub(s) as j_garcia said - depends on how much you wanna spend and if you can find complementary components to what you have. It would be easier (and probably cheaper) to get a quality AVR and use your speakers for R&L.