While I don’t know of any such site, I wouldn’t recommend it either.
Open source projects are made by the community, for the community, so I’d recommend you start by helping out one of the projects that you personally use. Maybe you can fix a bug that is bothering you, or implement a functionality that you are missing.
Communism does not assume that everyone wants the same thing, and it does take on account the “evil baddies”. This is all on the theory.