Amp question.

[CptGreedle]

Ok all you audiophiles out there, I have a question for you.
Since I am not a real audiophile (more of an enthusiast), I am not familiar with all the equipment used for the best sound and whatnot.
However a coworker of mine is an audiophile but is still relatively new to the whole digital age. He has a set of really really nice (and big) speakers that he uses to get 5.1 on his 65" HDTV. He uses a PS3 for Blu-ray, and an older 1998 Sony "Control Center". This is NOT a receiver as it does not have speaker hook-ups, and acts more like a pre-amp (if I understand that correctly).
Either-way, he wants to update this so he can have lossless audio, which means HDMI. Right now the best he has is Optical which does a smashing job, but he is always out to get better.
SO...
He is looking for a receiver that is not expensive (as the TV was expensive enough for him) that will allow him to hook up his AMPs to it. He says he has 3 amps. Two Carver Stereo Amps, 250 WATTS per channel (aka 500 WATTS per amp), which he uses for the from and back speakers, and One Denon 3300 Mono block 250 WATT amp for the center speaker.

Now I have no idea what this all is or how to hook it up, but he tells me they all have RCA in and another bigger 3-prong professional input as well.

What receivers are on the market that are not expensive and are able to hook up to these amps?