Best drop opition for 03 Denali

[03Dnasty]

Newb here but not new to the auto world just 4x4s. haha I've done a little searching but havn't found an exact answer. I just bought an 03 Denali and want to lower it a bit. I'm just over 116k miles and can tell the suspension is crapping out but I know nothing about the rear air suspension crap that this thing has so what all do I have to do to go about lowering it? I don't want to spend ALOT of money. What's the most common drop setup for this body style?

Thanks!

 

[NORCAL SS]

what is the max you want to spend? tell me that I can dial in a kit for you