You can't be in two societies it is one or the other. I do know it is mana intensive as an empath to gain favor for voln. Being lvl 8 you might have a better chance in mastering voln easier than say a higher level empath.

Also there is a lot of travel involved in Guardians of Sunfist, I believe every fifth step you have to check in at a certain location. Each society has pros and cons, I always tell everyone picking a society is about your characters development and role play.

I do not know much about GOS other than how to start out with them, however I am in Voln and some useful symbols I use are symbol of seeking which is useful for travel, symbol of recall which helps retain spells when raised from a death.

I am sorry I could not be more informative but good luck choosing. :)