I use a 3-component" system.  If the site is significantly un-level, I use what Camping World calls "RV leveling blocks" (and which do look like "leveling legos").  They are light (weight does matter in our vans), and store compactly.

For stability, I bought two additional Vanagon jacks on e-bay, and didn't pay much for either one.  I would have bought three, but you can't use a Vanagon jack at the right-rear, as it prevents the sliding door from opening all of the way.

For this one, I use what Camping World calls a "Stabilizing Base Pad" (basically an aluminum-pyramid-jackscrew").  As it is somewhat difficult to use, I first raise the right-rear of the van with one of the jacks, then slide the "Stabilizing Base Pad" under the jack receptacle and apply a little pressure.  Then remove the jack for use at one of the other corners.

 Try this:   http://tinyurl.com/3l4r9

Fin Beven
'90 Carat, Custom Camper Conversion
Pasadena, CA