Thanks Scott. I did a bit more research yesterday after posting. It looks as if you pretty much need an independant system or more of a onboard air system that consists of a much better compressor and the addition of a tank. They would still need to be separate switches/lines so my idea won't work. The other thing is the compressor I have now is not meant to run a long time and C.I.E J-Rod you're right that without a large compressor and tank it would take a long time. I would need a kit like this: http://www.viaircorp.com/OffRoad/10003.html
Jarod: Your right, but with towing a boat I don't think it will matter as much as if I had a camper on the back that I need to actually worry about having a leveled load without sway. I will purely have weight from the boat itself. But we'll see. I can always change it later. Isn't a hard project at all to do.