I had a tuff country lift kit on my truck for a while. I would say it is probably similar. Procomp, tuff country, skyjacker... they are going to probably ride a little stiffer than the more expensive setups and a little stiffer than stock. Honestly it is going to ride like a truck if you go with that setup. If you are anal about ride quality than it may not be the best setup. I would suggest an Icon, they ride real nice.
As far as sagging springs go. You can get sagging springs from all the companies out there. Seen Deavers, Icon's, tuff country, procomp... etc etc... The difference between the expensive leaf spring kits and the cheap ones are just a softer progressive leaf spring. If you are not worried and you don't care that your truck rides like a truck (stiff), then you will be fine with a cheaper lift kit. There are probably 10x the trucks out there with these kits on their than the others...