Have you a credit card? We put money into our credit card account before going and it made payments very easy. I think travellers cheques are accepted in far less places than they used to be, plastic is the norm these days. Plus you have to spend ages in the bank filling in forms and signing them, then when you want to use them you need ID etc., and if you don't use them all you've to pay another commission fee to change them back to euros.
As you're in Florida don't forget to check out the Universal Parks, in particular Islands of Adventure which is absolutely brilliant!