Suncoast is in Ft Walton, in the panhandle. I do not have one of their trannys in my truck, but in a previous career I put their units in several Fords in my fleet. The Fords all had stock power from 7.3s but were mercilessly abused, towing horse trailers, 5th wheel campers and such, well over 20K LB every week all over the country, and pulling special equipment up to 40K LB (!!!!) at low speed on private property, on roads for short distances, in rough, unpaved conditions and up loading ramps, and in other strange circumstances. They worked flawlessly and the service I got from Suncoast was second to none. This career, btw, was when I was with a world-famous business that is generally associated with Florida and involved enormous gray animals with long noses and people with strangely painted faces, big red noses and large, funny shoes. If you get my drift.
Suncoast does have "approved" installers who may be near you, and will also gladly help you as a do-it-yourselfer, or will help your favorite local mechanic with any questions he might have if installing a trans for you.
Another builder who is generating some buzz lately is Monster Transmissions in Brooksville FL. (not to be confused with Factory Tech Monster Box transmissions, which I think got bought by Jasper several years back) They're very near me. I have no relationship or any personal experience with them, but I am interested in checking them out.
Good luck
kevin