Hey,
As far as I'm aware you can do any of these FAA tests at any designated CATS testing centre. Check this link to find a suitable location for you.
http://www.catstest.com/
Alternatively you could just prep yourself at home and then be ready to take it as soon as you arrive at Sheffield or whatever other US based school you go to.
In addition to that, if u wanna spend some money well spent, take NoSig's advice and buy some books, the time familiarising yourself with it will be well spent.
NoSig always gives good advice.
Hustle On..
SH