I'd agree with cowlitzcoach. Get your bus weighed before you do anything else. Most truck upfitters try for a 40/60 front to rear and a 50/50 side to side weight distribution. I use air bags on my toad when I pull a trailer with it to give the rear wheels a bit more travel but you still need to keep the weight distribution right and also not over load the axle/tires. Bags will make the vehicle look OK but will do nothing to correct an off balance load--the inertia of the load will still be just as active as it was without the bags.