A lot of the leveling kit should be called "Future Problem Kits". 1" to 2" is about the max you can go on most because you put the axles at too steep of an angle and when you go over something and the front end goes up and the wheels go down the axles bind, they are engineered to be pretty much straight out from the diff to the wheel.
As far as buying a drop bracket, I don't think anyone sells just that part because it takes more than that to properly lift a truck. Depending on the kit it will have new drop brackets for the torsion bars or spindles that keep them in the stock location and bars that brace the drop bracket and a skid plate that ties it all together plus new longer shocks..
If you want to keep the height or level you have then you will need to buy a lift kit.
I have 2500 which is a different kit than a 1500, but most off the kits for the 1500 trucks and Burbs work in the 1500 AV it's the rear that's different from the trucks..
My lift kit have been on my truck for 230,000 miles with zero issues related to it other than possibly increase wear the steering components because of the bigger tires..
Randy