Heavy bags are pretty much just heavy bags.
Obviously you can get better quality bags with different fillings and different weights. But unless its going to be under strenuous continuous use in a boxing gym then all of them hold up pretty well.
Get a good, medium weighted one. Because your a beginner your power will increase, so not getting one thats too light is a good idea. The heavier ones may be hard on your hands too, but again as you get more experienced this wont matter.