Suburban/panel specific differences?
I think the only one would be the difference in shape of the sway bar. The sway bar is not used on pickups and trucks, so its only found on the Suburbans and panels. The Chevy and GMC versions are different because they attach to the front crossmember, which is different between Chevy's and GMC's.
If there are others specific to these models I'm not thinking of them right now.
The other differences are the same as on pickups and big trucks.