Well,
the best bet would be
http://www.stillen.com. Look for 1994 Nissan 240SX - this is the same car as 200SX in the UK. For some dumb reason Nissan heads like to mislead the people
Also, just to be sure, give them a call. Ask them if the parts are going to fit [they should] and maybe they know some good tuners in the UK.
Also, try
http://www.carparts.com. It's the same deal, pretend you have a 1994 240SX.
Maybe some of our mods know a lil more about this.