I'm in this, of course, but for the birthday project I suggest to come up with something more simple and feasible for everyone.
While a lot of us make art, fanfics, music, etc.; a lot of fans don't, but I'm sure they would love to join a collective birthday greeting as well, so we shouldn't exclude anyone.
And let's consider Minna too; wouldn't it be a bit awkward for her to be lavished with a huge pile of fan-made stuff?