Hi Jeff
We regularly attend rallies with our t/a Abbey 620 on all sorts of rally fields and all that I use are a couple of levelling ramps
http://www.towsure.com/product/2149-Level_Up_Blocks
and some chocks to prevent the caravan from moving back off the ramps.
http://www.towsure.com/product/2151-Fiamma_Wheel_Chocks
My levelling equipment is robust but lightweight and fits easily in the front locker.
When I enter a rally field I try to identify a reasonably flat well draind pitch. Fore and aft levelling is no problem and is done by the jockey wheel.
After finding the most reasonable part of the pitch I stop the unit in the place where I will pitch.
I place my ramps at the sides of the wheels to be raised with the lower part of the ramps in line with each hub.
I then reverse the unit in a straight line until the front axle is behind the rear ramp but to the side of it.
I move the ramps across keeping the same distances between each ramp until they are in line with the track of the wheels when the unit is moved forwards once more. Often the track is indicated by the tyre marks in the grass.
I place my two way spirit level
http://www.towsure.com/product/895-2_Way_Spirit_Levelling_Device
onto a flat worktop such as the front chest.
I then draw forwards until the forward wheel has climbed over the rear ramp and is starting to climb the forward ramp.
The rearmost wheel will climb the rear ramp by the same amount.
When the bubble indicates that the caravan is level apply the car and caravan handbrake, chock the caravan wheels and unhitch.
Then level fore and aft using the jockey wheel.
I always try to draw forward over the ramps rather than reverse to avoid the caravan brake engaging and also because it is much easier to unhitch after towing forwards.
When moving off after the rally I find that it's best to tow forward over the ramps but take care that the ramps don't kick up and dislodge the caravan waste pipes.