I've been mulling this over and I think I'm coming around to thinking the mass project is the way to go and I think that should be our focus from the gate.
The important thing is an underlying theme with some inter-connecting elements but not so heavy that the missions are dependant upon one another. A common setting and some important NPCs will tie things together nicely.
We'll need a simple website with the ability to set-up forums to start hashing out ideas; anyone up to the task? It can be bare bones since we'd really just need a few threads to work off of. I've only delt with wordpress myself and I don't believe they are set-up for that.