Glad to see you are bagging your truck. The most important part of bagging is to use good parts so you do it right the first time. I'd suggest 8 quality valves (1/2" up and 3/8" down will be plenty fast...you can go 1/2" all around if you like but it might be too fast), a good air compressor (engine driven or electrics are fine, plan on getting two electrics if you skip the engine driven), good air line, and good fittings.
A lot of people will tell you that you can lay out with a bolt-in notch in the NBS on 20s, but they are wrong. I had a bolt in and did not lay. Added a step notch big enough for 22s and the rear of my truck is planted. To use the 22s in your sig you will probably have to narrow the rear axle and tub out the bed. Any notch will do as long as it is quality as you'll have to fit it together and weld it in yourself.
Finally, make sure there are NO rubbing issues anywhere in your system before you even attempt to drive the truck. Don't assume anything as an air line not zip tied down correctly could get against your exhaust pipe and melt half way down the road. If a bag is rubbing something it will also fail causing you a lot of grief in the process.
The last thing you will need to worry about is your gas tank. The plastic NBS is pretty scary and the truck will lay out on it. I wouldn't suggest trying to drag the truck without raising the tank or getting a fuel cell. I have a devious customs gas tank in my truck and it allows it to lay out without hitting the ground. It is also a very nice piece of aluminum.
There are a lot of suspension hard parts available. I chose to go with the KP Components rear 4link plus "canti" attachment because it was bolt on, had great reviews, and gave good lift. You can use whatever you want, as long as it isn't AIM products. In fact, if you've already ordered anything that is from Chassis Tech or AIM throw it away and start over. There are a lot of front setups available as too. You can't go wrong with the Air Ride arms or some of the other arms available.
I hope this answers some of your questions. Feel free to post up if you have any more :shake: