I wasn't sure what direction to go either. I don't have air lockers, but will in due time. My truck is a reg cab 4x4 and space is very limited. I have a 5-gal air tank as well as a Viair 450C compressor and all the fittings, switches, gauges, air line, etc to have a full OBA system. I couldn't find a suitable place to permanently mount this setup without taking up valuable space in the bed since I'll be sleeping in there. There's not much room under the truck either. I sat on it for a while, then I decided to buy a compact portable air compressor. Mine is a cheap Smittybilt setup that I picked up at 4-Wheel Parts for $69.99+$7.99 for a 3 year warranty. This will air 35"+ tires and can do 150psi. It comes in a little bag, and has battery leads with clamps, coiled air hose, fittings, and a gauge. I can always add a small 2-3 gallon air tank for use with lockers, etc, although I've pretty much decided that I could get more use out of a nitrogen tank for that purpose. Anyway, that's what I ended up with, it's small and fits behind my seat even with the bench seat pushed all the way back. I've used the compressor a handful of times in the last month or so and it has been great.