Hi Steve,
Looks like the best solution for me would be EKs box and your mouse encoders. I'd like just cheap ArgoNavis like solution.
I do have 2 stepper motors though. I recently bought Celestron GTL 80 for $100 only. Used it for two nights and than blew it up 'cos of wrong connection, mixed + and -
You wouldn't think that power adopters are wired differently. Center jack should be + but in my case it was not? Blew up hand controller and circuit board on the mount, but motors should be OK.
cheers
bob