Hi Draw, your project seems really nice. The idea is great and the desktop interface looks good.
I just like to point it out, that, even if the interface it's 100% JS/HTML/CSS it doesn't mean it'll work wonders in all devices.
In a desktop interface you can have all those dialog boxes arround the corner of the drawing board, in tablets and specially phones, you can't. I mean, you can, but it'll be a horror show for people to be able to click the pencil icon that they want.
I hope you already have that in mind.
Another problem that I've had recently with mobiles was about drag and drop. For desktop I usually use jquery ui that work great. But the drag doesn't work for mobiles.
Anyway... I don't think here is the place to look for people to join the team.
Maybe you could try the Business Exchange section of the forum.
Good luck.