More Air ride questions!!

[2low72]

I'm going to purchase an air ride system with the nice tax return i'm getting, and have a question for all the experts, I pretty much know about the front set-up on 67-72 trucks. what about the rear with leafs. all i'm trying to achieve is to raise the truck for driving, not laying rockers (yet). with the Air Ride Technology's Air Over Leaf system help me achieve what I'm looking for, or is it more of a helper spring for heavy loads. and if it is do i need to change to a trailing arm setup? any help would be great even better with pictures. here's what I'm talking about
http://www.ridetech.com/productinfo/airoverleaf.asp