I am from Toronto, Canada. Where is your brother from. I experienced the same things your brother might having moved here many many years back. I can explain to him in detail with first hand knowledge and experience. Please have him contact me or perhaps you can provide me with his information so we can talk further about his current real estate needs.
I have been working with alot of buyers from Canada lately. Now is a great time to buy with all of the inventory and the current exchange rates! To anwser your question your brother would be taxed as any other American however if the property will be a second home he will not be able to claim the Florida Homestead exemption. To learn more about the Florida tax laws you can visit http://www.bcpa.net . Good luck in your search!