Anonymous 1
It's normal to desire to live someone. My advice is don't put pressure on yourself just because your looking for a partner. Not everyone falls in love over night.

I'll advice he start by becoming friends with becoming friends with the opposite sex, you never know where some of these friendships could lead.

Anonymous 2
I'm really sorry about the situation you find yourself. It's a difficult situation. I'll advice against such a move because it doesn't always work out. You could get married to his best friend and not get over him which could lead to having extra marital affair, you may never feel comfortable been married to his best friend.
There is just a lot of ways this could turn out.

Just move on from Jim and find someone else outside his clique to avoid stories that touch.