I am looking for a hubs for a medium-duty tandem axle trailer would pull apart have anything that I could use? Do they have a selection of tires and rims that you can purchase without having to remove them?

As far as the trailer parts go I went looking for some parts for the one I had and I didn't have any luck but as far as the tires go they have a pretty decent selection I have purchased many tires from them and had very good luck there so good luck and happy shopping.

The closet thing to a medium duty axle would be an axle from a 1 ton pickup. If that does suit your needs then yes they do have some of those occasionally. Wheels an tires is a hit and miss, your probably better off buying a set somewhere else.