Let me suggest that before you buy any seeds you first check-in with your county extention office.
Gardening in Florida presents some unique challenges, equalled only by folks gardening in south Texas. Your planting and harvesting schedule is different than the rest of the country; you sometimes have to take special steps (such as using shade cloth in the summer), etc. The extention office will have booklets and instructional sheets, and the agents are available to answer specific questions.
If you opt for open pollinated and heirloom varieties your seed purchases will be a one-time expense, because you can then save your own seed for reuse each year. Plus, in a small way, you help fight Monsanto's goal of dominating the world's agriculture.
When buying seed it is always a good idea to use a seed house as close to home as possible, because their seed already is adapted to your conditions. I would certainly recommend Tomato Grower's Supply Co., in Fort Meyers, both for that reason and because they are one of the top-rated seed houses in the country. In addition to tomatoes they supply seed for peppers and eggplant.
Although further north, Southern Exposure Seed Exchange, in Virginia, has a wide selection of heirloom seeds, many of them from the South. So that would be a good choice as well.
Mariseeds is a great outlet, particularly for tomatoes. I don't know how many varieties Mariane Jones is offering, now, but it must be several hundred. Although tomatoes are her main thing she also offers some peppers and a few other veggies.
Roger Postley, of Tomatoes Etc., offers seed for more than 100 heirloom tomato varieties. You can reach him at RPostley@aol.com
For beans, check out the Sustainable Mountain Agriculture Center. Bill Best offers some of his varieties (he has about 450 beans in his collection) for sale through them. Or you can purchase beans from me. PM me for details.