+1 for islandmandan
A class D amp is the way to go if you want hi-end performance at a reasonable price. Owners of mega-buck power amps rarely have positive opinions of them, however, because it's just too embarrassing how similar good class D amps sound to their amps for so much less money.
You can buy complete amps or build one in kit form if you're handy and want to save even more money. They offer extremely low distortion and background noise levels combined with very good power levels and dynamic range performance. They also offer exceptionally good bass response and overall a very accurate and neutral presentation from top to bottom, very much like the audio ideal of 'a straight wire with gain' that doesn't add or subtract anything from the inputted signal.
If you prefer a warmer sound signature, you can always utilize a tubed preamp to alter or flavor the overall sound to your preference. Since good class D amps are so neutral, all changes to the quality of preceding gear are more easily discerned including preamp type, preamp tubes, source components, recordings and even changes to interconnect cables and power chords.
Based on my experience formerly using good quality class AB amps (Adcom, McCormack and Aragon) in my combo music and ht system and now utilizing 2 stereo class D amps (a ClassD Audio SDA-440-CS for rear surrounds, an Emerald Physics EP-100.2SE in bridged mode for the center) and a pair of D-Sonic M3-600-M mono-blocks for my main speakers, I know the class D amps outperform my former amps in all the categories I care about.
Class D amps not only perform better and cost less than class AB amps in general, they're also smaller, lighter, cooler running and use a fraction of the electricity compared to class AB amps. In my opinion, there's really no need to consider a class AB amp unless you have the budget for the top brands like Pass.
The benefit of going to separates are typically better performance and more flexibility in upgrading.
Tim
