Looking for a R9 280 replacement

I'm running just a single R9 280 for fun. But I moved up to Ubuntu 16.04 and the new drivers don't support it. Does anyone have a 290 or something else in the supported list that'll do 15-20Mh or so? I could pick something up off of ebay but I'm hoping someone has something laying around that I could pick up cheaper.

Thanks!