Sorry, to hear about your situation but it is great that you are looking for alternatives.
By using different materials, you can put that grip where ever you want and it will be strong enough.
You just need to reinforce accordingly and it will likely take a couple of tries to figure out how you need to get it done.
The forces on an offset grip will be very different then in the conventional location so the method I used (wood, epoxy and bondo) will see more flex then it was designed to handle.
Maybe a block made from alum with the grip extension offset as you need it will be the best solution.
Anything is possible.
Good luck with your quest. Ever consider a bullpup?
Jerry