A couple of things I would consider as possible options.
Uhaul or similar, and/or Home Depot.
Both rent pickup trucks at a fairly reasonable rate. I am not positive that you can take the Home Depot trucks out of area though, like to drop off at a distant locale. Probably would even check with standard car rental options...and there is always Uber, etc.
I would have to be in dire straights to ever get on a Greyhound bus (again) and the last time I did I was really young. Still recall it as a very negative experience.