Do I need leaf springs for load capacity or travel?

I'm building an off-road camper that will see 50% paved highways, 50% moderate wheeling. I want about 3" of lift, but what confuses me is the consensus on application of various leaf spring packs.

People say the Dakar's are for "load capacity", and others (such as Deaver) are for off-roading and don't handle load so well. Well, I will be off-roading with several hundred pounds of load. (Snug top hi liner, roof racks, camping/off-roading equipment, sleeping platform in the back, food/water, eventually bumpers and skid plates). I'm hesitant to use the word "overlanding", but eventually I'd like to get there.

I like the price on the Dakars, is anybody using them in off-road priority application with 600+ lbs of crap in the bed? If so, are you still getting ~2.5" of lift? Will I need an AAL on top of the Dakar set? While we're at it, recommend me a shock...

 

For around $600 Alcan in Colorado can custom make you a custom set of leaf springs that can handle the amount of weight you intend to have in the back of the truck. I called them the other day and was impressed with their knowledge and customer service.