Hi, I'm trying to put together a home theater system with the front L/R speakers rated at 50w-200w and these are the ones I'm most concerned about, for stereo music. I want to buy a receiver that can give me 150wx2 to drive the front L/R speakers and 100wx2 to drive the rears (5.1 setup). Can somebody tell me if this is possible, or if all amps come in standard 100wx5 or 150wx5 etc? What brand/models should I be looking at? I'm not looking to spend more than $500-600 (new or used). THANKS!