Did your old Yamaha amp do the trick with those speakers? It takes a lot of power to be heard over drums. I played drums for years with a similar setup and I have some significant hearing loss as a result. I strongly suggest some protection, though I know how I reacted to that advice...
If your old Yammy did the trick I'd look for something with similar power capabilities. I'm not as up on receivers as some of the other guys here, so you'll probably get some good suggestions. $500 (or less) should be able to get you into something pretty decent.