Also, go on musicians friend. Click on keyboard amps and SEE what kind of amps are even for sale. Why not do some research and find out make/models and whatnot before simply asking "what amp do I need." See when you say not too expensive, and loud enough to be heard over drums, I would say Traynor K4. The Traynor K4 is something like $800. For you that'd be expensive. For me, that'd be a budget amp, because anything else and I'd be buying either two powered speakers (JBL eons, or EV) or passive speakers and an amp (QSC power amp and two accugroove tri-112). This would run up to $1500-2500. So yeah.
By the way, I'm a little frustrated over other situations. I think I might have taken out some of the anger on this post. I apologize. But seriously... do some research for yourself. Read product reviews. Find what's out there. Simply posting on a forum "what amp is best" I'm sorry, is just friggen lazy.