pulling a trailer w/ bags on bars

I got some questions about building a rear suspension to pull a 18' car hauler. I want a good bit of lift because it is on a 72 suburban b/d on 22's. The only way I think of getting any lift and good ride quality is to put the bags on the bars instead of on the axle. Any comments or pics will be appreciated. I also looked at putting some triple conv. bags over the axle but I know they take an ass load of air to fill. thanks