I can't give any input on going from torsion to coilovers but I did make the swap on a RCSB I am building. Drop spindles, Viking DA coilovers for the front, flip kit for the rear leaf springs, Caltracs, smooth body DA Vikings and the kit to relocate them behind the axle. EVERYONE I talked to before I ordered it thought it was the best money they had spent and guys are cutting 1.3 60' with the setup I just mentioned. My Silverado isn't being built to DD but as a weekend hellraiser and track toy. If I was to lower mine again I would do spindles DA coilovers, ditch the rear coils and bag the back with smooth bore DA shocks. On my Yukon I have spindles, adjusted keys, DJM rear hardware kit, 5305 coils, helper bags in the coils, Belltech shocks, and an adjustable panhard. I am very seriously considering getting larger front and rear sway bars as I do more research on them but if you are on the fence do it. I have yet to hear one person say one bad thing. And Richard aka Atomic is local to me and is as good as gold.