Check out this page from Brown Aviation Tools. It has a pretty good assortment. You can always find cheaper or used elsewhere. Like the yard.com. When I buy a rivet gun I will be getting the Sioux 3X. We use them at work and they are awesome!
http://www.browntool.com/Default.as...1&Level=a&SortField=ProductName,ProductNumber
He's wanting a pneumatic blind/pop rivet tool I would say, not a rivet hammer.