I'd go with a 10lb CO2 bottle and be done with it. I've burnt up several of those under $150 compressors.
For $250 and around $10 each fill-up, I went with this system. (mine is the 15lb one though)
http://www.offroadairstore.com/servlet/Detail?no=7
You could go all season on your small tires. I use mine on my crawler with 37's and get about 1/2 season of wheeling fill-ups (about 6) before it runs out.
Find a fire extinguisher store for the best refill prices on CO2. Mine charges $9.50 to fill my 15lb tank. You can run air tools off of this too. I'd skip the expensive regulator and just get the fixed 150psi one.