It depends on how many you think you are going to do. There is one marketed by both Arrow and Stanley with a swivel head that takes four mandrel sizes that works pretty decent. About $45 if I remember right. The swivel head can be handy on inside rivet jobs. One of the nicest rivet tools is made by, surprise, Pop Rivet Co. (most people do not realize that Pop Rivet is a trademark). It is well over $100 and you have to go to industrial supply stores to find it.
If you are talking hundreds of rivets, consider a pneumatic gun.