Help deciding which amp to use

I have a Nakamichi Av10 and nak dvd and cd, von schweikert speakers (all of them are vs). Anyway, I am wanting to go with separate amps and use the pre-out on the nakamichi. Today, at the local thrift store I picked up a Rotel 2 channel amp and a b&K 3 channel, and a parasound that will need service but is 2 channel. I was thinking B&K f/c/r and rotel rears, and then eventually parasound r/l B&K ceneter/rears. Opinions, advice? I should get much better sound out of running those amps instead of the receivers amp, shouldn't I? About the thrift store, I have to do a little bragging- the B&K and Rotel were 75 bucks each working, the parasound was 25- were they nuts?!...hehe