I chose the 'Air Lift' bags. (Firestones will work just as well)
They work great and are 'adjustable'. That's what sold me.
As far as adding air at the camp ground is concerned, you can use several different methods. I have a compressor that I use at home. I have a bicycle pump I keep in the storage compartment of the trailer.
You could get a little portable 12v pump from wally world.
It doesn't take much at all to pump these bad boys up. If you have the budget then you can opt for the on-board compressor.
Just my 2-cents worth
(which if added to $5.00 just might get you a gallon of gas)
Bill