I recently saw this surgery that seems to be having good results for some people who can actually have it done. I just wanted to share this, since I had not seen this before and it seems like quite a novel approach:
Basically it is an implant that helps regain control for some people with SCI, and is being done with good results in South America.
In the meantime, all the advise given by others seems on track as well. Be well, 10C