What kinda flooring you have? I put a piece of leftover wood flooring under one end of my stand, and finished the rest of the leveling off with some newspaper. After the tank was filled i cut the excess newspaper off with an exacto.
My floor is unlevel every which way(front to back, side to side) so the newspaper worked out great to get it perfectly level and not wobbly. I sat an old tank on the bottom of my stand(25gal empty) and sat on the top of my steel stand with my 1 1/8" board on there and a level. I got on and off until I was good to go. When my water level is down a bit it looks great.
actually I just had someone complimenting how level the stand was, he could tell by the water level