You have two caliper brakes, then? You might have thought of getting a disc. If you are thinking of wheels, then so too is it a time to ponder using a disc, as that affects wheel choice.

The venerable Avid BB7 has been a staple, but new mechanical brakes in the offing tip things in the direction of a disc, such as the TRP Spyre, that weighs less than the new lightweight BB7, and squeezes bilaterally.

If you release at least the rear rim from its heatsink mission, your wheel choices expand.