What are you guys using? I have a Viair 450 on my Superduty with a 2.5 gallon tank which works great but not so much room on the Jeep so I'm thinking either a portable or something mounted. Definitely do not want to give up the factory AC compressor so 12 volt electric it will be. I'm thinking of another Viair, only the portable one. Don't want a cheapie that will let me down when I need it, it will be for the road only, I have a shop compressor at home.