OP: Amps are so cheap these days, that you can easily buy an amp stack that has all the power you will ever need, and in the future only buy receivers with pre-amp outs and use the receivers are pre-amps and video switching units. This method is gaining popularity today. If this is the route you want to go, I recommend getting amplifiers with a minimum 250-300 watts per channel into 8 Ohms, and be sure they are also 4 Ohm capable. Note: you will need a dedicated 20 amp circuit to feed your A/V system if you have this much amplifier capability.
On my stereo systems (I have two), I use high power component amplifiers now. On my main system, I use a high quality receiver as a pre-amp and source selector. My 2nd system is for the computer, so I don' t have a receiver as a pre-amp on that; the computer is the main source and I have an audio mixing board I use for source selection.
-Chris