well, neither.
To raise the rear, get airbags. most do this just for looks. airbags even plumbed separately will not do much for sway (or stable loads).
To control sway, get a helwig sway bar. the stock 5/8 sway bar is useless with a camper.
I wont use the upper stableloads as they put way more force on the upper overload mounts than designed for. I won't use lowers as they prevent the spring pack from resting flat on the lower overload leaf.
When full compressed, the whole pack, including the upper and lower overload leaves, all lay flat on one another. Either stableload device disrupts this and puts all the stress in 2 spots.
This is just my engineering opinion... Others have had good experiences with them.