moose,
Is this all suspension lift, or a combination of suspension and body lift? Did you do the lift yourself, of have it done/bought it that way?
Off the top of my head what I can think of is, Stock Height Springs and mounting hardware, shocks, any lenghtned steering components, possible lenghend driveshafts, axels may have been truned slightly to help with driveline angle.... smaller tires and posibally wheels if the wheel width is to wide.... and I would say expect to have to replace at lease some if not all the fastners as they may be damaged....... I might replace any fastners just to be safe.....
If there is a body lift, you will need stock hight body mounts and hardware, and depending on the body lift height you may have to remove any extensions for control levers wire harness.... any filler panels behid bumpers that have been added to fill the gap.....
These are just some things that I can think of, you may not have all of them listed but just trying to cover all the bases, and I am sure that other will add more info.
As for the replacement parts, if you are wanting to go back to stock height, I would look at wrecking yards and get stock parts.....