pre-amp processor

My suggestion is bring one of those $6k marvels home, hook it up and listen to it. Then just for kicks do the same with some used $500 stereo whatever. Anything. Literally anything.

When you hear how much better the sound quality is, stop and think: Is multichannel really worth it? Really??! 

Mr X :I am a farmer and I want to buy a tractor.

Mr Y : You should buy a bike. It is less noisy 

It depends on what you want. If you are looking for good sound quality buy a preamp (2 channel audio preamp). If a surround processor is required ,and you want equivalent sound quality, then you need to spend a lot more money.