I am not sure what your final goal is but let me just offer a suggestion/advice I was given a long time ago. So many people try to add/remove/modify components and end up sacrificing one thing for another. Think of it this way, you can't have a strong house without a solid foundation. I am assuming that you are just looking for a way to level out the ride height of your truck. By adding air you gain that control however loose the proper handling characteristics originally intended for the suspension and will probably cause premature bushing and tire wear.
For my K-10, I knew I wanted to have a level ride height, smooth ride, and safe suspension (this is just a daily driver with 4x4 capabilities for the winter). I went to a reputable suspension shop (the real ones that do big truck work and not the guys who just know how to bolt on airbags or add in blocks with longer u-bolts) and told them what I wanted. Basically the right answer was to put in new leaf springs in the front with a bigger arch. They of course readjusted the driveline angles (which was negligable for a mere 1 1/2" or so front lift), put on new shocks (6), new rear leafs, all new bushings, and 4 wheel aligned it for $800.
No offense to any bolt-on guys, I just am a proponent of building a strong foundation at the base level therefore not having to clutter up the suspension with bolt-ons. If it is a lowering effect you are looking for (without the hopping capabilities), they can also give you leafs with less of an arch to an extent, as well as adjust the size of the coils for 2WD models. Either way, to each his own and good luck with your project, show us some pics when your done or throughout the process.