As Brian said, it is really a good idea to talk to the people at Miami Tropical Bonsai. And I'm glad to see you are taking classes. This will help you in many areas of bonsai. And you will get to know other local bonsai growers.
Pinus radiata - Monterey pine - native to a very small region of California. This pine has been widely planted in sub tropical and tropical areas for pulp and timber. It is more ''tropical climate tolerant'' than Japanese black pine. It can be styled very much like a JBP. Except for the bark being more flakey, and reddish, it is a relatively good substitute for JBP. You might try one of them. They are also a 2 flush and possibly a 3 flush pine. Really tolerate warm winters well.
Casuarina and Allocasuarina - these 2 genera are from Australia and New Zealand. There are at least 2 that have become invasive species in southern Florida. They are leafless, in that they use green stems of twigs to do their photosynthesis. In Malaysia, Indonesia and parts of Australia they are used for bonsai and can be trained to give a very pine like appearance. Beefwood and She-oak are 2 of the common names for this genera. I think they do well in the Miami area. Ask about them at Miami Tropical Bonsai. I think you will like what you hear. You can probably fine good ones to collect along drainage ditches, roadsides and possibly for sale at Miami Tropical
You seem to be suffering climate zone envy - forget pines, embrace what grows well around you. There is a diversity of cool things in the Miami area that nobody in other regions of the country could possibly grow.
Get yourself over to Redland's Fruit and Spice Park. It is about 20 miles southwest of downtown Miami in Redland.
https://en.wikipedia.org/wiki/Fruit_and_Spice_Park
24801 SW 187th Ave, Homestead, FL 33031
I've always heard the park talked about as being in Redlands, but apparently it is technically in Homestead.
Wander about, take pictures, taste the free samples in the visitor center. As you wander the park, note which species have naturally small leaves, and fine branching. These are the species that will have some ''bonsai potential''. If you like their flowers and fruit, that is even better. Take photos, smell the flowers, crush leaves and smell, and taste fruit.
Then after leaving the spice park head over to Robert is Here Fruit Stand. - 19200 SW 344th St, Homestead, FL 33034
and get yourself a Sapodilla smoothie. Or Pouteria smoothie, or any of the Passion fruit and other exotics they have. You might even get to taste a Mangosteen, allegedly one of the best tasting of the tropical fruits. Myself I prefer Sapodilla, and or ''Chocolate Pudding Fruit also called black sapote" - Diospyros digyna or D. nigra
Anyway the Fruit Stand will have fruit if in season, in quantities you can buy to take home where the Fruit and Spice park will only have samples you can taste on premises.
Embrace the fact that you can grow cool species for bonsai that also have good to eat fruit that nobody living more than 30 miles north of you could easily grow.
The park was part of a demonstration project of the USDA plant crop introduction and commercialization project. Parts of the park were first planted in the 1920's basically testing which exotic tropical fruits could be grown in southernmost Florida.
So if after visiting the Fruit and Spice park you still want to grow pines, I'll leave you alone. But really, the first time I visited the park, I was at an orchid festival held in the park, I was enchanted with all the exotic trees and fruits and spice trees I saw. It should change your life - LOL - just teasing, but it is a seriously cool place.
