if you find clicking the mouse is the sore part, check out where i modded a deathaddler with a cherry switch, it alleviated my index click finger, actually from day one it went from sore (over weeks of annoyance) to "WOW".
i've since modded a cm storm with both left and right click cherry switches, all smooth and nice, btw my mouse switches required 70g to activate, cherries are 45. That's why mouse finger is sore imo.