Guild Wars 2

I just have enough for one of these skills. I am level 40.

Which should I get at the moment for Events/WvW?

I like to play Support role with spirits buffing allies, and healing allies when I can. Thats my favorite role. So kind of stuck between these two skills. which would you all suggest?

Any suggestions on which to get?

Elite Spirit is quite could and it also revives/cleanses.
Unless you need the stability from RaO I say go for SoN.