This..

http://cgi.ebay.co.uk/2-100w-TK2050-...item519760c047

Is a ridiculously good amp at a stupidly low price. It can be upgraded with a rotary encoder volume control for just a few quid more and there are many, many sites detailing upgrade opportunities. I had the four channel version and it sounded great. In fact, I intend to get one of these at some point and put it in a nice box from modushop.