Like this Low?
Custom made struts with "collared airbags" for the front.
Airbags on the rear to replace coil springs.
Remote swichbox for up and down, side to side, front to back
Digital air pressure gauge of all 4
Chrome air tank with 12v compressors on each side. Electrics, solenoid valves, air lines, and logic box for remote tucked behind it
Without labor it ran near $4k in parts. I've seen some bare bones ones without the remote or pressure sensors and gauge, plastic line, one air compressor, and black painted tank for just under $2k. You won't find one specifically for the GXP. You have to get a universal GM kit and have a very qualified welder with airlift experience fabricate those front airstruts.
You don't want them breaking, and drilling the holes just right to keep camber/caster within drivable limits is important.