I would go with a regular hanging heavy bag, those stand up one's, no matter how much shit you put in the bottom there is no resistance. But, if you are going to get a standing one get the bob. It's good for certain things like clicning and getting used to hitting in certain areas, but again not much resistannce.
So if you can get a heavy bag, get that, even if you don't have a place to hang it try to get a stand if you don't mind spending extra.
Stand The standing bags are good for when you are just starting out but when you develop power they don't work very well.