Then I guess you've read this thread? :D
viewtopic.php?f=2&t=13881
But anyways, you can make a metric ton MJ out of any MJ. You just need some heavy duty springs, shocks and rear axle. But for the camper, you'll likely need even more than the metric ton leafs can give you (like the sir springs that Luke added). And more braking than the stock system can give you. Personally, I'd look for a longbed that was as close to stock as possible and ran very good and build it up with all the fun upgrades that are out there. I'd add a disk braked 8.8, the double booster mod, some sort of disk brake upgrade up front (I wonder if liberty brakes can be adapted?)... Maybe it's for the better that I don't have any money. I'd be blowing it on building more MJs. :D