I think you will find there is a lot of info on UAS's on this website if you look, not only in the military aircrew forum. Eg, the one called "UAS's to close" or something of that ilk, you may see that you may not have an organisation to join.
EMUAS, I remember them but we definitely drank more beer and went to the bathroom less....
Regards
DS
Ps BTW, if you are asking the question, is it for all types of flying or just those interested in the RAF, then I guess with a username like that you shouldnt be too difficult to spot in the interview