Plenty of people run Superlifts without major issues.
Keep in mind though, that if you go with the Superlift, your stock driveshaft won't last. Superlift sells an upgraded driveshaft, but it's at least $300. And then there's all of the suspension parts that you might want to replace while you're tearing everything apart. It's not necessary, but it's good assurance.
Another alternative is the body lift. Many people are against them, so I won't go into detail. However, many people run these as well, without issue.
These topics have been covered numerous times, so do a little searching through the forum, especially the suspension section. You'll learn a lot more than what any one person can tell you.
-2003 Edge Lowlife
My soul is empty and full of white girls