Hitch, motorcycle caddy, and load helpers?

[Pance]

So I've been looking a few bikes lately and I would like to be able to transport a bike with my 9-3.

I like the idea of this:

http://www.motorcycletrailer.com/mag1/caddy1.html

The problem is the tongue weight. I don't have a hitch as of yet, but all the ones I have looked at have a tongue weight of 165-200 lbs and I am running koni springs and struts so this would be a low ride.

The bikes I've been looking at would be a stripped down bobber style bike so the weight really shouldn't be over 500 lbs. They say 2/3rds of the bikes weight is on the tongue which doesn't seem like it would be, but still on 500lbs that's 333 lbs of tongue weight.

Is this completely illogical to do? Has anyone done this?

Also are there any load helpers, springs or airbags to counteract the rear end sag? I do crank up the struts as stiff as possible which helps somewhat...

And yes I know it specifies for a Class II hitch and the 9-3 hitch is only a Class I.