If by cap you mean canopy, then yes it should work. These trucks have not significantly changed since 2005.
I removed my rear spoiler to install the canopy (leer 100r). I replaced it with some kind of rounded over plastic thing from Westin that works like the older trucks. I think spoilers came...
The factory blue and yellow Bilstiens are too short and weak to use with the OME pack, and besides, they are junk anyway. I used the Emu Nitrochargers to save some $$$, but many folks like the Bilstien 5125 as well. In hindsight I will probably wish I went to a rebuildable shock...
Get the EMU...
I just swapped out my Deaver 2leaf AAL for the full OME MD Leaf packs w/ OME Nitrocharger shocks. I can tell you it is Night and Day better. Don't waste your money on an AAL.
I have a Deaver add a leaf 2 leaf pack setup... I hate them. The squeak so badly it drives me nuts. I now have the full OME suspension that just arrived that I will be swapping in.
Tip, if you do the add a leaf pack and you can't make it stop squeaking while you figure out a replacement, spray...