I really like this garden

I'd placed a window planter to give some appeal to the window. I think palms and cactus would be a good starting point. I would probably put some accent piece like a sun dial as a focal point in the garden. This way it would be easier to plan what would compliment it.

You can use Lantana as a flowering shrub. It's a desert plant, takes heat and drought. Fragrant and butterfly/hummingbirds delight as well.

I would use 2-3 large potted evergreen drought resistant tree bushes to help with shading the sitting area. Line them up evenly spaced along the sitting spaces, space between them. Looks like you could use a deeper overhang. Maybe a trellis pergola. Cactus and large rocks and tree stump accents may help.

Vinca also thrives in the heat.
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That is your entry? Gets a lot of sun? I vote for an arbor, to the left t of the door, and while I know you want low, maintainable plants there, you are in Fla. where things are pretty lush. I don 't think cacti would work as well as some dwarf native shrubs would going up the front walk. Pot some lemons and put them on either side of your door.