Those are the air bags setups, they are expensive but the labor is a lot cheaper if you have a shop do your air ride & it would be real easy to return to stock if you ever decide to return to the regular suspension. The shock portion is the same though as the Hal 12 way shocks.
As far as being able to go lower with te regular bag setup thats not totally accurate, I have done both setups on trucks & there is not a noticeable difference in the height. Now if you want to cut stuff up the the old setup will go lower.
We all should know by know that these air ride kits have no "performance" value to them, just looks.
If they could prove it did i'm sure Ed would be the first in line <G>
Mike @ No Limits Motorsports
94 BBB Stock 14.80's
93 Typhoon Stock ?
67 Chevelle 11.50's