There are no such arms that prevent wobble on a standing desk. Especially with a desk with 2 legs. You can mitigate the wobbling but you can never prevent it from happening. I use an Ergear monitor mount/arm and it mitigates a lot of movement or wobble. I use two monitors, a 29” Ultrawide horizontally as the main and a 24” regular monitor on the right vertically with these arms and it barely wobbles/shakes. This mount does not actually have an arm portion that extends out so there is hardly any movement. If you get an arm that pivots then you’ll get a lot of wobbling.

I personally prefer post mounts to monitor arms. They’re more stable and if you need a monitor extended come in armed varieties as well. One per monitor still comes in way under budget.