My bags were a kit for a ford excursion/F-Super Duty with manual controller/gauge, and compressor from summit. Air lift brand. With MANY hours of tinkering and several different 'setups' I was able to modify a pressure switch from a dead garage compressor for use as auto-ride. My system is extremely custom and perfectly tuned to my daily towing usage, but if I had had the money (And not already had this kit collecting dust in the garage) I would have gone with another of the kits out there..you know, one that didn't require half a million mock ups, two sets of mounts, seven weeks, hours of grinding, and a welder willing to climb under my truck in the snow for a bottle of crown.
There's a ton of setups out there, but for most practical uses, just get the bags with mounts, and the valved hoses. You can route the hoses to almost anywhere on the body (Such as the rear licence plate, or fuel door), and unless they are damaged or you want to adjust it, the pressure won't need checked more often than your tires. If you want to go the more complicated (and pricey) route, There are kits that offer from as simple to a manual switch, to wirelessly controlled, programmed, and monitored digital consoles for the cab.
DO keep in mind, for every component that is added, such as a tank, aux air output, etc, that there are more points where air can bleed off, which means the compressor will be used more often. Also, tanks=condensation, which especially in the winter = ice blockage, settling, expansion, and corrosion. With the simple bag/hose setup, there are only 3 points where air will bleed off: The bag, Connectors, and the hose. With more elaborate setup, more issues arise, and the price of these components is insanity compared to just a kit with valve-stemmed hoses.
Don't misunderstand, I love my horrid little mad-scientist-esque air setup, but it's FAR from worry free, and if it was something I'd BOUGHT as is, rather than cobbled together myself, I'd give it terrible reviews..lol. Unless you do a TON of towing/hauling, or constantly have more than 200# in the bed all the time, I'd keep it simple. If you want to go with something more elaborate, be prepared to spend a lot of money, and troubleshoot fairly regularly.