If you don't have the wet environment that they need to grow in, then there is not much sense even trying. If you do have the wetland, it will take a long time to produce a tree of any size.

The best way to store any seeds is to dry them in at room temperature out of the sun. Put yours in an envelope to transport home.

As for germination--you'd have to ask someone down there--like an arboretum. I don't think there are many here who grow them

Drying the seeds is probably not the best way to go here -

Not that I grow them, but in looking for you I find these are really interesting seeds, and they begin to germinate while still attached to the tree before they are dispersed into the water. I find too though that if you are 2 hours from the ocean, you may only be able to sow and grow them on in an environment like a salt water aquarium so it's not likely they are going to make a successful keepsake from your trip.