I do know different types of bike racks require different type (size) of hitch. I would recommend finding the bike rack first, then get the hitch to fit.
I got a used Yakima bike rack a few years ago. Because my car is not rated for towing, I had to consider total weight of rack and bikes. Therefore, I was limited to a two-bike rack vs possible four-bike rack.
I also found out different bike racks will accommodate different size/length bikes. The wheel wells on my rack are not adjustable, and will not fit all bikes.
Laura Schwenker