Need Headphone amp under $300?

I'm in need of headphone amp under $300. I'll be buying some cans in the future as well.(Sennheiser HD-580's / Beyerdynamic DT-880 or AKG K-501's ?) Prefer to stick w/SS. Creek is coming out a new model, the OBH-21 I believe. Sumiko makes a model as well. Anyone familiar w/these models or could you recommend something else in this price range. Thanks, Bill.