I've just about settled on the Firestone airbags. I'm still on the fence regarding an onboard compressor. It would be handy, but I would like for it to be able to operate airbags and also switch over to air up truck and trailer tires. I'm sure it could be done with a crossover manifold with shutoff valves, but I'm not sure how I would do it do that it did not look like a rocket project and a plumbing nightmare under the truck. Has anyone successfully done this?