There was a really neat tree with some strange looking fruit that we
found later appeared to be a type of guanabana tree. The fruit was
sort of like a mango, pulpy and yellow inside (didn't try to eat any
of them

Maybe one of these two?
http://en.wikipedia.org/wiki/Annona_squamosa
http://en.wikipedia.org/wiki/Annona_glabra

(the first one seems like a closer match to your description of the
fruit). Those are the two which seem to be in my field guide to
Florida trees, anyway.

We also have some ear tree seeds we would also like to grow.

Meaning this one:

http://en.wikipedia.org/wiki/Enterolobium_cyclocarpum
http://botany.cs.tamu.edu/FLORA/dcs4...w15039944s.jpg

? If so, it is said to be relatively easy to grow from seed
(according to the first of those pages).

You might need to seek out some reasources in Florida (native plant
society, garden club, etc). It is really a different climate (in
terms of what grows there naturally, or can grow there), even compared
with Georgia or South Carolina. My tree book has pages and pages just
for Florida.