Best Bags for Lightweight Vehicle

So I have this friend who has a vehicle that is very light. His current setup rides very firm, so he's looking for some bags of some sort (sleeve bags?) that will ride best on a vehicle that is very light weight (little lighter than the back end of a minitruck). Any suggestions?

Thank you,Aaron

I see what you did here.

What about the smaller Slam Specialties?

Being that you're a hydro-guru, you could talk his wife into letting him put hydraulics on it. :)

What kind of bags and setup are on it now? A sleeve bag is an option for an over axle setup. like a firestone f9000. Another option would be to put more leverage on the bags that are on there now.