[ASTROPHOTO] Autoguiding using an old webcam and an arduino

I'm in the early phases of designing and building my own mount (powered by stepper motors) and this is a huge help!

I'm pretty new to this all though, and have a few questions:

I'm planning on 2-axis guiding (both RA and DEC). How can this be changed to work with a dual-axis guiding system? I can probably figure out how to tweak the arduino code myself, but will the ASCOM driver still work? How would I need to change that?

Also, out of curiosity since I'll need to be buying my own, which pololu stepper driver did you use?

Thanks!