Tim, I am a little unsure about what you intend to actually do with a F First if and when you get one..Are you intending to race or just drive at test days/circuit days, or are you interested in sprints and hillclimbs perhaps. If the latter is of interest there is a class for F Firsts in the BARC CCC Speed Championship, mind you they are amalgamated with FF1600 cars. Check out
http://www.barc.net for further info. Hope you find this useful.