We have similar problems and the solutions are not many. Assuming you do not want to exceed your tow hitch limits and the GCVWR of the coach, the best you can do with a gas coach is 5 - 6k total tow weight. When you look at trailers you will probably exceed the weight limitations with a steel trailer, alumimum is much better but much more expensive. The hydralift idea is a non starter for my coach and my bike (a Goldwing), once you do the numbers it exceeds the rear GAWR and GVWR with the coach loaded. So we have kind of settled on either an aluminum Featherlite 14' trailer ($5 - 6k) or the Race City Products tandem tow dolly ($4-5k). Our toad is an '07 Mini Cooper so I still have to verify the clearance of the ramps under the Mini, just haven't got around to that yet. As far as the weights go, they stack up thusly:
14' trailer - #1300, Mini - #2500, Wing - #900 = #4700
RCP Dolly - #950, Mini - #2500, Wing - #900 = #3900
Since we weigh 21600 loaded, full tank of fuel and water, (on a W22 chassis), the trailer option pretty much maxes us out, the dolly leaves a couple extra pounds...
2003 Pace Arrow 36B, W22 Chassis
Ultrapower ECM upgrade, CAI, Wires, Koni FSD