Doors – What are these doorstops called

I'm not sure about ChrisF's suggestion since I've never had that particular problem (with the door rubbing on the hinge side) - is the issue that it's hitting the frame on the hinge side or the doorknob side?

If it's hitting the jamb on the doorknob side (as if the door is now too wide) then the usual solution is to trim down the door. Usually I would run it through a table saw, but you could do it with a circular saw as well if you are really careful.

Just make sure to trim off the knob side rather than the hinge side so you don't have to worry about mortising out new spots for the hinges (and then risk being off on the top of the door)

This would depend on the tools at hand. If you have the proper chisels and jigs using a blank would be fairly easy, and you would not have to worry about squaring and plumbing the frame.

If you only have a 4' level, a hammer, and some shims hanging a pre-hung door would probably be your best bet.

A third option is if you could find a pre-hung where the hinges would line up with the existing frame, you could simply hang the pre-hung door in the old frame. This option eliminates almost all the work.

In my opinion, if the existing frame is true I would rather use a blank. Most pre-hung doors come with really cheap crappy frames (unless you pay extra for a good one), so any time I've used one I ended up building my own frame anyway.