Basically the idea is to install heavy duty manual jacks.
Scissor jacks for the back (these are rated at 7500 lbs each :
Camco 57421 RV Olympian 24" Scissor Jack, Pack of 2 : Amazon.com : Automotive
And for the front the recommendation was an ultra Fab Power Twin II Stabilizer jack set for the front.
Ultra-Fab Products, Inc.| - Powertwin II Electric RV Leveling Stabilizer PT II-22
Parts would come out to between 900 and 1000.00 with install adding 2 -4 hundred if the dealer did the install. You would then pick up a 5 -10.00 adapter to spin down the jacks with a drill and pick up a 1/2 inch drill at the local hardware store.
I have the drill and tools to spin down the jacks so no added cost for me there but to add in the cost there here is my drill : (120.00)
Shop DEWALT 10-Amp 1/2-in VSR Pistol Grip Drill at Lowes.com
So max out of pocket expense installed and out the door would be around 1600.00 with the added benefit that I won't have to futz with hydraulics, less weight added to the rig, and I can manually operate the jacks if I have to. I don't know if the front can be spun down with the drill but I am hopeful that a 3/4 inch bit will fit. My sisters trailer has electric jacks and they are too slow to extend. If I can run the fronts down with the drill I should be able to get level in 5 - 10 minutes on even a tough site. If I don't have to back on and off of blocks the Mrs and youngsters will be able to start setting up camp while I level which will save even more time. That much closer to beer thirty!
Of course that is all out the window if I'm at a national park and faced with a 5 degree slope. Some blocks will be needed to keep the wheels in contact and weight on the suspension but even then, backing up onto a 3 stack of blocks/chocks and running the jacks down to another block stack will be much faster than repeatedly resetting blocks for the wheels.