bang for the buck is leafs. they are cheaper and simple. I live by the KISS(keep it simple stupid) method. A good quality leaf will wheel great. if you have to ask yourself which setup you need most likly you wont need links. air shocks make a link setup cheaper but not to friendly on the street you would need coilovers which raises the cost.
I choose to do leafs due to wanting to keep my truck on the road. I want to be able to wheel the piss out of it but drive it to and from the trail. On out of state trips I will tow it but want to drive it too and from work on occasion and to the trail. later if it becomes a trailer queen then I might link it. for now leafs will do the job nicely