Before you add any of that....
Load the RV and have the front end aligned. That will make a world of difference.
I added a beefier anti-sway bar in the rear because I am towing. But just that and the alignment made it very drivable.
The Safe-T-Plus is valuable on a front tire failure. It will return the steering wheel to center. But (IMHO) does nothing for drivability.
__________________
|