Congratulations, it is indeed a big responsibility to undertake such a position.

I don't know is there is a way of identifying and contacting the leaders of other Armigerous Clan Societies for advice.

Wiki has a list of them under the article about Clan Cunningham:

http://en.wikipedia.org/wiki/Clan_Cunningham

Along with the interesting information that there are now two contenders for Clan Chieftain with a possible petition to the Lord Lyon for recognition after legal advice.