Greetings 

I am looking for an amp that will power my Hi-Vi Research Swan M1S Speakers. 

The specs are as follows: 

Power: 10-60W 

Sensitivity: 86dB/1m/2.83v 

Impedance: 8ohms 

Frequency 48Hz-20kHz 

I am hoping to buy used and keep it under $300 preferably. Vintage or newer is fine, tube or solid state is also fine.

I would really like something that delivers a fast slew rate/speed to get that nice articulation of attack and decay on notes, as well as good, tight power and punch, particularly in the mid range. I am really trying to avoid the thin/dry and boring sound - I want something musical, baby! Think body or fullness! 

Thanks in advance! Any opinions or suggestions are greatly appreciated. 

p.s. I mostly listen to classical music, and singer-songwriters like Norah Jones. Occasionally electronica/trip-hop and punk rock (clash, BR, etc.) - but who cares how that sounds as long as it is loud and obnoxious :) 

Thanks again.