I use the 12V Viair 400P-RV compressor. Hooks up to the battery terminals. Not cheap (and the price on Amazon is currently 30 percent higher than I paid a few months ago) but a great compressor, with great reviews. Comes with a carrying case and some "RV" accessories.
I store it in my TOAD, a Jeep Cherokee Trailhawk, and use it when I offroad. I "air down" for a softer ride, and the slightly bulging sidewalls help protect the wheels from rock damage, then back up when I'm off the trail.
I also added the same compressor as a built-in on my PC, along with a 2 1/2 gallon tank that stores air for more volume. I had it installed because I put airbags on my rear axle, but it also works great to inflate the RV tires. It is installed under the floor and on the frame so it is completely out of the way. There is an air connection on the side, next to the battery tray, to hook up the hose for tire/toy inflation. Not a cheap way to go, and I wouldn't have done it except for the airbags, but it works great!
Bob
If I did not have the airbags, I would just have the single Viair 400P-RV.