Leveling and stabilizing are different things.
Probably the best and safest soluton is to have jacks installed aftermarket.
I would not reccomend any method of temporary jacks under a frame to level---IMHO it is a bad idea to be moving around in a coach with temporary jacks of any variety holding it level and stabilizing even if only raised a small amount.
If you just want to be level then something under the tires can do the job-----there are plastic plates sold for this or you can just make 2X10 boards do the trick----basically just place them in front of the tires and drive up on the boards staying centered on the boards front to back and side to side------------------If you have duals you need boards under both duals and best to level each side equally with what ever you use under both front and rear tires.
You will still rock and roll.
I do all my own stunts
03 Dolphin LX 6355, Workhorse W22, 8.1 vortec, 04 CR-V, Blue Ox, Brake Pro----Norm, Barb and
Doc(He's a PhD)