Are you travelling, or working in a studio? The only relevant part of a backdrop support is the horizontal bar. The vertical support depends on where you're working. So, if you're in a studio, consider hooks into the ceiling, suspend a suitable bar from a loop of chain (which will allow you to adjust the drop from the ceiling) and hang your backdrop from there. Make sure the hooks into the ceiling do anchor properly of course!
You may need several pairs of hooks, depending on the layers of backdrops you want suspended, or any versatility in placing them in different parts of the studio. This does free up floor space.
Andy