There is also one COMSCC event at Summit Point this year. I've driven with them for 3 years when I lived up in the Boston area, they are similar to what your describing as a European club. Come out, 1st day is practice, 2nd day is time trial and then Open Track. May 7th and 8th. I highly recommend them, I've driven with NASA, and SCCA and I've never had near the amount of time on track that I get at COM events.
Check them out, you will not be disappointed.
www.comscc.org