all you have to know is the angle of the bearing race which has to be 45 to work with ethic forks, all integrated headsets are that but alot of cup headsets have 36 and fsa is known to do it often. your one is a one off size as is and the specs off the fsa site do not give any angle reading on only that headset, the rest are there though. only thing you can do is go to a shop and see if one fits.
edit: to what i can see of their tech drawing it is indeed 45 but better safe than sorry