Not trying to discourage you, but if it's your first boat, Tortugas trips and Bahamas crossings should not affect your purchase. Find something you and your family will use and get comfortable with and then move up as your experience grows. With the budget you are working with, moving up doesn't seem to be an issue.
Gulf Stream Crossings and Tortugas Trips can get extensive in planning, weather, blah, blah, blah. Get comfortable and then you'll know what boat you need for an adventure such as these.
Good Luck with your boat choice, and hope I didn't come across as trying to be your dad!