Yes, gators everywhere down there.....they'll leave you alone for the most part but, there was just a lady killed/partially consumed by 2 gators I think down in Myrtle earlier this summer....that will give you the warm and fuzzies.
Just FYI, a "good," wide SOT yak is plenty stable for standing and if you don't have the best balance, you can buy a simple outrigger for them. For fishing w/ gear, dry storage, regular storage, ability to sit comfortably, etc. I would def. recommend the yak over the paddle board. He can even use it in the surf to get out deeper for spanish, etc.
If he gets one with foot pedals and rudder ($$$) he can fish miles and miles everyday and be in great shape too! As Pork said though, storage can be an issue but if he is able to store it somewhere free or cheap, that is the way I would go if I lived down there (well, I'd have a boat or two, too!).
Sounds like he will be living the dream..