Looking at various sites and reading responses in forums like irv2, I decided to get a Viair Portable Air Compressor model 400PA-RV (P/N 40047). It came yesterday afternoon!
This compressor connects to your 12V car or RV battery and includes two 30' long stretch hoses that can be connected together to reach all of the RV's tires no matter how large it is. The package includes the compressor, a nozzle with a pressure gauge, hoses, a connector to fill "normal" (not the inside tires) tires, an extension so you can reach in and fill the inside tires (for dual wheels) and a kit of small adapters to fill things like rafts and balls. It uses no oil, will fill tires up to 150 PSI and has an automatic shut-off function so it turns itself on and off between tire fills.
I got ours on Amazon.
Here's Viair's Youtube video: