If you intend to carry a compressor in your RV, there are not many that are really up to the job. I have a 2-gallon Campbell Hausfeld tank type compressor that can get my rear duals back up to 80 psi but patience is needed. I need to let pressure build to over 100psi to get air to go into tires that have 70psi in them. My compressor is handy for motorcycle and bicycle, tires, basketballs, etc. Best to contact mfr, tell them what capability you need and get recommendations.
Here's a Sears unit that has had some good reviews for topping off 80 psi RV tires.
http://www.sears.com/shc/s/p_10153_12605_00915309000P?sid=IDx20070921x00003h&srccode=cii_5784816&cpncode=31-153213016-2