No problem at all.
Your instructor who will be checking you out will show you the local area and procedures to use.
You will also have an hour or two of ground school which the instructor will use to go through airspace, charts, weather minimums.
The checkout will be signed off as a BFR in your logbook if you haven't had a BFR or FAA checkride within the past two years.
Don't forget to start the verification process with the FAA and CAA at leat a month or two in advance. This is required to be issued an FAA PPL under FAR Part 61.75 (based on your JAA CPL/IR). It will be limited to VFR privilages only unless you take the FAA Instrument Foriegn Pilot written exam (see FAR Part 61.75).
http://www.caa.co.uk/default.aspx?ca...87&groupid=612
http://www.faa.gov/licenses_certific..._verification/
As for aircraft availability, you will find the warriors will be busy so if you would like an aircraft to tour around then book your slots before you go... don't forget the four hour daily rental minimum if you are going to take an aircraft away for a whole day.
But saying this the warriors aren't as busy as the cessna's... most people do the ppl on cessna's so the warrior aircraft are usually used for instrument ratings and commercials (before going onto the complex). I wouldn't take the chance on availability though.
Hope this helps.
Charlie Zulu.