I've run a TGC 1.5'' and a Rize 2'' spacers on top of Carli 3'' coils against Sage Carli's recommendation. Ride did suffer. The additional height caused the control arms to be at a much steeper angle making the ride rougher. We backed out the compression valving in my shock since I figured that with a 2'' longer shock I would have more travel so I could go a little lighter on the valving. It really didnt help all that much.
For control arms I used the Procomp ones off their 5'' lift. The problem was they pushed my axle too far forward and my track bar would hit my diff before full compression. To properly lift the truck 5'' I also needed a track bar drop bracket, an adjustable track bar, drop pitman arm, longer shocks, longer limit straps. longer sway bar end links and longer bump stops. In the end it really didn't work out so I kept the Carli coils and got the rest of the Carli parts for a complete system used in the way it was desiged. It was AWESOME on and offroad. I can stuff 37'' tires under my 3'' of lift and not rub anywere so I really dont see the need for me to go up a couple more inches in lift.