My fav-o-rite mouse(r) of choice:  Boy, is THIS easy.

Jesse 

A4 Tech - Battery Free Wireless Optical Mouse

They have several models - mine is the NB-90 & it's just brilliant.

It comes with a special mouse pad that powers the mouse so the mouse itself is cable & battery free
& it has 6 different buttons & two wheels that you can program/set up to work the way you want it to.

I love it - it works better than any other wireless mouse I've ever used,
(& that's despite being dropped on many occasions & having coffee spilled on the mouse pad several hundred times  ),

AND it only cost about £12 (plus it saves me spending a fortune on batteries)

I personally use a Logitech Trackball (right-handed). I only got introduced to it from my dad when I received my school laptop and had confined space. I've never had to deal with any sort of pain in my hand since using my trackball and it even works for some Savage 2 gaming here and there.