Try poking around over on Audiogon.com It's an auction/classified site for consumer audio gear, usually better stuff. There's bound to be pre-amps and surround procs there at a reasonable price.

I'd make a recommendation but it's been ages since I've played with consumer gear. Ayre, Classe, Krell, Linn, B&K used to be good brands the last time I played with their equipment.