@MMarciano,
There are far stronger fences than think I saw you had, and strong fences can also be built over major strong foundations - but I agree you guys might as well go for a wall, because of being in a hurricane zone besides the weight of the big dog.
A super strong fence would likely jar with the less weighty construction of the arbor, etc., whereas the brick look wouldn't.
The wall can be block (cells filled with concrete and rebar) on a concrete foundation with heft and rebar, with a brick face (veneer or full brick). Ahem - I'll mention contacting a civil engineer for a consult given the sand problem, and what is reasonable to do and what might be overdoing it.
I don't know how they build walls in Florida, I'm used to building re earthquakes.