You do not need a massive budget to have a good suspension under your truck. You do, however, need to select quality components and do some R&D if you want a good ride. Would you build a deck on your house using bits of plywood and old scraps of fence posts? Of course not. There is a right way and a wrong way to do things.
Atlas, Deaver, Alcan, National and several others will build custom spring packs. It is CRUCIAL that you corner weight the truck, completely finished, with people, gear, water, food, dogs, etc. Multiple thinner leaves will ride better than one or two thick leaves. Getting the right measurements is also very important. The factory FE/FG springs ride like crap because they are poorly designed, thus, there is quite a bit of head room for improvement here, without investing hundreds of hours or tens of thousands of dollars. Rough estimate: $1000 per corner for good springs.
Damping control is essential. A high quality, cheap damper does not exist. Quality costs, once. Get something that is adjustable, such as a Rancho RS9000, if Radflo, ORI or ADS is not in the budget. You can upgrade later. Rough estimate: $150 per corner. If you can afford it, add an off-the-shelf air bag with a manual controls for load leveling. Air bags are NOT shocks, but they are springs and can assist in damping vibration.
This is really about the best option for an inexpensive suspension that rides well. You don't need millions of dollars, but taking time to do it right, once, instead of guessing or using inferior components will make your camper much more usable and enjoyable in the long run.