DynAudio Audience 52: What Amp?

I currently have these running on a mid-fi Yamaha A/V receiver, and while the sound is Ok, I would like to add and external 2-ch amp to open them up and let them sing a little bit more :) As most people know, they like the juice. Looking to spend sub $500......I have a few questions.

Do I need an integrated amp? Im guessing I do not and that the yammie can serve as the pre-pro. Although, are there any benefits to using an integrated?

I would like a warm sounding amp. The Dyn's are reveiling, and the yammie is on the bright side. Will a warm sounding amp offset this condition? Im hoping it will.....

Power. Not sure on exact room dimensions, but Im guessing they are in a mid-sized room. Right now the yammie puts out 100wx5, 20-20khz, %0.06 thd. Im guessing I will need an amp with at least 1 & 1/2 times that power to notice a difference. Although Im assuming a will need something that will provide substantially more current that the yammie due to the speakers 4 ohm rating.

Thanks for any and all suggestions.