Need help! Anyone know a heavy duty rivet gun?

[In The Ten Ring]

Here is my problem.

I have been hired to repair the broken latch from some 30 lockers. Some of these I intend to fix with my drill and by using nuts and bolts to attach the new latches but others will best be served with a rivet.

Can anyone link me to a rivet set that can do this job? *All I have is a pop rivet set and that's not good enough.

I want rivets as they will allow more room over sheet metal screws and that's what most of these lockers came with originally. Also, the construction of the lockers often does not allow access to the backside of where the latch attaches.

These rivets have to be tough and strong since each locker will hold about $800.00 worth of uniforms, skis, and gear.

*I might be able to use it on my truck later!

Can you guys help me out?

I'd like to keep things to no more than $50.00 but I could go higher if need be.