This may be one of
This may be one of the most customizable mice I have ever seen. The magnetic mounts used to allow swapping of the outer shell and buttons is simple but ingenious. That beauty isn't just skin deep though, because customization doesn't end at a colored shell. The Ambi features two programmable buttons on either side of the mouse but if you don't use one or more of them, the kit comes with extra flush button covers that disable the button and smooth out the side of the mouse. Even the sensor position can be adjusted from front to back to find the best balance for your hands.
The included software is simplistic but gives you great freedom. The mouse can store four profiles, each with fully programmable buttons, up to 6 dpi settings, adjustable polling rate, sensitivity, and even pickup distance and debounce delay for clicks.
This is a very worthy mouse for southpaw games or anyone not interested in an overly-ergonomic gaming mouse design.