I think my air hammer is a CP 7150, but if it is, it's earlier-production with black paint instead of CP Red like the web sites show. Burp-Guns only become useful once you have a hammer bit (chisel) suitable for the work you're doing. There's fifty+ different styles of hammer bits to choose from.
While I prefer the longer ones, I wound up with a short set of Old Forge (I think) bits which were made in USA. Bought 'em years ago. They've held up well. I have a couple of Snap-On exhaust pipe cutters, a Snappy suspension-joint picklefork that I don't use any more, and a few odds-and-ends. I bought my Zip-Gun to remove rivets holding ball joints to the control arms of my K1500. At the time, I had a 120-volt POS air compressor. Took me all day. You're going to figure out right away that you'd better have a REAL air compressor.
Best to figure out what you're likely to use it for, and then buy quality bits, than to buy some universal bit set where all the supplied bits don't serve any purpose for you. OTOH, the useless bits can give you some blacksmith practice as you heat them up and re-forge them into a useful shape.