The fronts are the only thing that need any assembly, in which case if you had to do it yourself you'd just need to rent/borrow a spring compressor. The rears install as separate components.
Anywho, I have 4 SRT springs new in the box and rear Nivomats with ~50miles on 'em (from 2007 Charger SRT). If your car already has sways, they are the same across all models (except police package - 30mm in rear in that case, not sure about front). If you're interested let me know.