While you are ordering your pneumatic pop rivet gun you should invest in some of these.
http://mrotools.com/cleco-fasteners....FUlxQgodNzMAsQ
These are great to have in your tool box.
We don't carry our compressor when we travel. We use the manual rivet guns in our travel tool box.
Take a look at our robot this year. We used about 200 rivets to put our robot together. We did a lot of lock and tab joints where we create a tab that fits in a rectangular notch to locate a part. We then rivet it together. Places with high stress have screws and pem nuts instead of rivets. We also made use of a csk punch tool to csk our pilot holes for the rivets. Keep in mind you don't need a massive amount of rivets to join parts together.