Well I opted to jack up one side and will take two trips to the tire store (it's right by my office anyway). Jacked, then jack-standed the frame behind and in front of the axles. I just chocked the other side and snugged up the corner scissors for good measure. I guess it was easy for me since it's not registered and the tires are probably unsafe anyway.
Just raising all 4 on the leveling jacks sure is tempting though! They are on the frame, but on the corners. They seem like fairly solid jacks, but I can't find any rating info on them. Dry now, it's like 4200#... about 1000# per jack.