Basically you don't have any visa problems because you are already qualified.
You have to get a temp Airmans cert off one of the FAA examiners in the area and also complete a Bi-annual flight review, which you can do as part of your check flight for the rental. Whoever you choose to fly with should know whats involved.
The radio procedures are very slack so just stick to what you know and you will be fine. The area controllers all use correct RT and the only problem you might have is the speed of the RT. And don't be suprised that if you call in with Warrior 440 for example they come back with charokee 440, and a c162 is a skyhawk i think.
The first time you go into a decent sized regional airport can be a bit stressfull especially at the weekend, when you can get Lear Jets etc flying VFR and some quite fast singles knocking about.
Don't try to do a deadside join, the locals won't have a clue what you are doing and will just ignore you and proberly cut you up. Cross mid field at 1500 then 45deg entry to down wind at 1000 seems to keep most people happy at uncontrolled fields. Circuits in general are tight and can be extremly busy at the weekends. If you do large circuits people will take the **** by asking what type of bomber you are flying.
And from what i have seen if you turn up with cash most schools won't turn you away.
The other thing to watch out for is most schools have a deal with the local council and will only pay 1.50$ a gallon so if you decide to do your 300 miles qualifier you can be stung quite alot for the refueling.
I found Britannia, Winter Haven pretty good for hour building because they will pay back 2$ a gallon which means that you don't lose so much if you do a trip down to the keys and back. ( this might have changed now so check)
Places worth a visit.
St Augstine - oldest town in florida, still younger than my local <img src="smile.gif" border="0"> i had John Trovalta take off behined me in his boeing.
Space Coastal - 25$ taxi ride to NASA
Cedar Key - great fun runway and don't be suprised when the local taxi driver asks if you want a lift on the RT and she has a dog in a pink cardigan. Its well worth going to lunch there the shrimps are great.
Everglades - another fun runway in a cross wind.
Ormond Beach - h'mm worth a visit just to see the famous school which has produced more PPL's than any other, food is OK as well. And also cross charlie airspace to see the Daytona race track and watch the sharks cruising up and down the eastern sea board. And at the weekend watch out for sky divers dropping into Flagner.
Keystone - Real redneck country and a dog which attacks your plane when it takes off. (you don't want to get stuck here for the night!!)
And of course the Keys do a decent fuel plan for the trip as fuel is quite expensive the further out you get. And ask at the FTO for motels they can get very good discounts for you.
The only other advise is get as high as you can.
a. its cooler
b. the locals can't be bothered climbing that high so no traffic problems.
c. you can't get lost because you can see both coast lines (or should i say its alot harder to get lost)
d. if the engine goes and your at 8.5k you almost always have a strip within gliding distance, unless your over the everglades.
e. you don't get bounced around by the thermals and pissed off with gliders.
The only thing i would suggest you read up on is the american defintions of airspace and the current NOTAMS and interceptions, SVFR rules are different than at home as well.
Have fun
MJ