Originally Posted by
AOD_CapnVG
If you want to stick with Corsair with more buttons, check out the Corsair Scimitar. Comfortable right hand ergonomic shape primarily for palm grip. Mouse is designed for MMO/ MOBAs, but will do for fps games in a pinch since it uses a 3988 optical sensor (it's good). By no means an fps centered mouse, but will work fine for casual and semi-competitive play.
Logitech G502 is another one that might fit you well. Heavy mouse with adjustable weight, awesome 3366 sensor, and a fair amount of buttons.
It'll be difficult to do find a heavy fps centered mouse with lots of buttons, as the industry is moving in the opposite direction. Your best bet is mice designed not for fps, but still with competent sensors.
Could help more if I knew more about your hand size and grip style!