We found an aluminum tripod stabilizer on Craigslist. I'm glad we didn't pay full price because the beneficial effects on our 40' unit are noticeable, but not miraculous. Andersen jack blocks or similar may be just as effective. Scissor jacks at the rear may be even more helpful. "X-chocks" dampen some movement, too.
On our previous 32' unit we had arms like the steady-fast system, and found them marginally effective.
If you're going to be more stationary, and the movement bothers you enough, you may wish to take more steps to calm the wiggle. If you're going to be traveling from place to place often, you may have to find a balance between how much wiggle you can tolerate and how much effort you're willing to spend to reduce the wiggle.