There is no "best."
Sometime you can find a used Audiomat Arpege in that price range. It would be near to lower side of the power I would want. Very musical amp though.
Also look at the Ella from Diyhifi as a kit.
http://www.diyhifisupply.com/diy_kits/the_ella.htmlThe Ella works nicely with the "Django" TVC available at the same place.
I've made a couple of them for relation. They do not need a pre. I pair them with a diy version of a Caroline Audio single driver speaker. [url]http://www.carolinaaudio.com/[/url]. Or you can use something less expensive.
Sincerely
I remain,