As for mice with ability buttons, I can't say I've tried one, but judging by the poor side button placement most mice have, and that the vast majority of "gaming" mice are designed for palm grip (I claw grip), I've never been willing to drop over $150 (AUD) on one only to find I don't like it.
I used to bind abilities to the numberpad and have movement on the mouse, but it's downfall was the loss of the ability to strafe. Then I moved to a Logitech G13, and I really love having a thumbstick for movement. My gripe with the G13 though is that according to Logitechs own reps, the thumbstick was aimed at being a form of quick select for FPS players, and not for character movement, and as such it's rather un-ergonomic.