Hey! I just stumbled across your post. If you are interested, I am the guild leader for Catharsis. We're a pretty casual guild, and everyone is friendly and willing to help out. We're a mid-sized guild, but a lot of us are young professionals so the guild chat is fairly quiet most of the time.
If you and your brother are still looking for a guild and are interested, let me know! We can chat a bit more and I can introduce the guild a bit better as well!