You will lose some downward flex with the adapters. The new shocks extend longer than stock.
Northridge4x4 offers Bilsteins with the 2.5 kit but you have to call/pm them.
I had the Bilsteins and now use TF 9550's. The Bils run more firm on road.
If you have the stock (black) shocks, I would upgrade. Another option would be is to find a set of Rubicon/upgraded gas shocks (red) and buy the kit with extensions. They will work fine for you