I'm new to the world of separates, but considering I want to eventually upgrade to an entry level hi-fi system, that's the way to go, especially since I can keep the same amps every time a receiver breaks or I want to upgrade to new technology.
I won't be buying this all at once, but I need to upgrade into it slowly. I made an earlier post about my Yamaha RX-V2095 being broken, and the pre-amp section works fine, but the power amp (for the main left channel) is not functioning properly. So I'll definitely need to replace that ASAP with a 2 channel amp of 100wpc or more.
Right now I have Polk RTi series bookshelf main speakers, but I'll replace them with Definitive Tech Power Monitor 500's. I'll most likely buy a Denon DVD-2200 that has 24-bit Burr Brown DAC's and connect it directly to the receiver's 5.1 input.

So my question is what amp to buy? Someone suggested NAD, but I'm not familiar with them (or anyone else). I'm just familiar with Yamaha receivers, and know that it sounds better than Sony receivers, and is in the same league as Denon. I'd like to go a step or more up from that. I'd like to eventually be able to get 7 channels of the same type of amp, so I could have consistent sound. I'm looking for a sound that'll definitely not be rolloed off, but also not harsh or too bright. I'm looking for a very natural sound that'll be clear on classical/acoustic and be very much on time and dynamic with electronic music, and be excellent for home theater. I'll eventually be looking in the total $3000-$5000 range for the entire pre-amp/processor/ 7 channels amp range, and would like to find a good 2 channel amp (guess $1000 or less would be proportionate to that price range) to go with the Def Tech's. I'm also not sure what pre-amp's are good.

Any help is appreciated. Thanks!