Well these are impossible questions to answer if you ask me. Its going to be different for each person, each speaker/room/system combo, etc. Are your speakers here to stay for a while?
If it were my money with your speakers, amps that would make the list of consideration:
Blue Circle's offering in your price group
AVA 500
Jungson JA100
Usher R1.5
Butler 2150
UcD based amps (channel island, et al) if you like the sound (some love it, some don't).
Dodd monoblocks
It also matters whether you cherish soundstage, imaging, presence, prat, forward or laid back presentation, etc, etc.