as a former Air Ride Tech/Ridetech employee and now dealer / installer I can say the tri five kit was one of our top 3 selling kits. They are a dirrect bolt in with slight modifications to the coil spring pockets and welding the lower 4-link cradle to the axle.. The kits come complete with every nut, bolt, washer, wiring harness, and fitting you'll need.
For you guys running C-4 suspension or a custom IFS they have them available as well.. The over all ride height will be dropped 1.5-2" from factory and you will have 5" of over all suspension travel from top to bottom 2" up 3" down.
Ride quality is second to none once you tune the shock valving and play with the preasure ( you can adjust the air pressure 1-5psi with out effecting height but change spring rate) to achieve the ride quality you want, since every one has there own opinion of a good ride quality.