If by treasurer you mean the guy holding the community's bitcoins, it doesn't make sense to go with anyone but john. His security is tried and tested and has been for years, he is a brand and one of the pillars of this community.
I would advise against a single guy for escrow.
Only bitcoin-savvy people will be on board, so why not use some form of distributed escrow, like casascius' approach:
https://bitcointalk.org/index.php?topic=129552Also, if you use the distributed escrow, I'd be willing to be a "treasurer", just overseeing the process, not holding any funds.
If John K goes rabid, we might as well shut up shop; the community is dead.
