It depends on your budget and space available. There are bags that are supported from the ceiling and others that are on a stand. I guess you don’t want to get one that hangs, especially if your place (room/home) doesn’t support that type of weight. I would go around and visit different stores to see what they have available and ask their associates to help me find the best one. It would also be a good opportunity for you to try out a few of them and get a better feel as to which one would work for you. They come in various shapes and sizes and their price varies as well. Maybe a kickboxing instructor can give you a better answer and visiting a boxing gym might be a good idea.
I hope this helps.