For the series I have here on Tap, there's Alex, a secondary character in Heavy Horns, who has a prosthetic leg.
For other things I'm developing, I have a main character with one arm, a blind guide, a guy with a synthetic heart, an albino who's legally blind... that's all I can recall off the top of my head at the moment.
As for recs, I highly recommend A.M.P. The main character is wheelchair bound. He has prosthetic legs, but they aren't usable as of yet. He's a sweetheart and I may have a slight crush on him. Lots of action, great art, and it's just getting started!