Ok, I’m back after working on the shifter for a while and I was able to get it down to quite a small size.
http://www.brickshelf.com/gallery/Rl...allshifter.jpg
It is basically all still the same. The only difference is that the worm gear now only actuating one shaft instead of two. (For sake of space saving)
All I need to now is figure out the motor mountings and then I will be ready to actually implement it into a robot!