Hey, I'm from SoFla so maybe I can help with the heat/humidity thing.
Texas Blue Giant has been a terrible splitter for me. Maybe it's our rain, maybe our humidity, either way, I'm not gonna keep my tree. It's very similar to Brown Turkey and I'm not really wild about BT in the first place. I think it needs arid climates tbh.
Smith is heaven. You have to get it when it's really supple and leaking honey. ahhhh
Emerald Strawberry is also a great choice; its strong skin holds up to rain and its tight eye makes it almost impervious to ant infestations. Kinda tastes like plum more often than not.
Violette de Bordeaux does really well for me as does Hollier, LSU Purple, Tena, and JH Adriatic. Although JHA tends to split sometimes, the flavor's good enough for me to overlook it.
For Black Madeira, seek out Figo Preto; it's the same varietal but just less diseased with FMV. If you're dead set on buying "Black Madeira", go with the strain from username KK. We had a member a while ago who said that I258 was the least diseased version of Black Madeira but I don't really see any resemblance between the two, visually anyway. Hmm.
Either way, good luck and be careful of rust. Use copper fungicide on the leaves and when watering, don't get any of the leaves wet.