Steve as everyone else is telling you, its all about CFM and the volume needed for long processes like sandblasting or painting. If you find a portable one that comes anywhere close, you need to let us know. I don't know of anyone who thinks they have enough of a compressor. Most everyone lusts for more. I started with a Sanborn 7hp single stage upright. Added a second unit the very same stats in tandem, giving me essentially 120 gallons of air and a single two stage 7 hp compressor in practice. It works for sandblasting, painting, everything, but just barely. If someone has a spare 20 grand they arent doing anything with, I will get the correct compressor for the job. LOL!
I DID go as cheap as I know how. 2 60 gal compressors is less than 2k. Others have much better setups than me. Also, others have better knowledge of this issue than me. Just sayin.