Installing a Safe-T-Plus is easy enough, but I'm skeptical about it being a solution. It really just stiffens up the steering wheel. Improper tire pressure is a common cause of wandering, so is incorrect ride height. If the suspension ride height is off, the front end geometry will be off even though the alignment values are in spec. A really good alignment shop would check that, but I don't think most of them do.
A call to FCCC Customer Help line (1-800-FTL-HELP) should get you some suggestions. And the optimum values for alignment and ride height for your specific chassis. Better yet, make an appointment at FCCC Factory Service in Gafney, SC. It's not all that far from your area and the service is superb. Reasonably priced, too.
The best alignment and front end shop in Florida is JoSams in Orlando. It's an adjunct to their main business, which is the manufacture of truck alignment equipment. They REALLY know alignment.
2004 American Tradition; 2014 Buick LaCRosse
Homebase in the Ocala Nat'l Forest near Ocala, FL