Might be worth looking into motorized telescope mounts. Should have plenty of precision, although you might not be able to slew very fast and will probably have

Might be worth looking into motorized telescope mounts. Should have plenty of precision, although you might not be able to slew very fast and will probably have to handle zoom/focus/camera control separately. Looks like people have built and documented open-source telescope mounts, or you can buy a cheap one for a couple hundred dollars.