If on a budget, the Vixen Super Polaris has about the best setting circles in that class mount.. NOT the Great Polaris, but the older Super Polaris. It is a excellent mount, and the circles are far more useful than the later GP mounts. At least that is my own opinion.

Another benefit of the Super Polaris is that some models had a RA drive that ran off a single 9 Volt battery.. WOW!

Next up on the ladder is the GM8. A bit more mount than migh tbe required for a 4" refractor, however they are of course heavier, and much more expensive.

Good luck.