I've been using one of the 2hp, 150 PSI, Porter Cable Pancake compressors for over a year now, and it works great. It will air up your bus tires and doesn't take up a great amount of storage space in the bay. I bought a remanufactured one off eBay for about $129 including shipping. This is a link to one like I have. I had a small Coleman before, but it would not do the job. http://cgi.ebay.com/NEW-C2002-Porter...2em118Q2el1247