To sum it up, you want to create a project based on your own concept and its general direction will be urban fantasy (i.e. quasi-regular world with extra supernatural elements) with bits and pieces of hi-tech and horror elements. So essentially it's Blade Runner kind of theme?
The general concept seems to be functional, but it still depends on execution so yes, if you want people to get involved you'll have to put up a site or at least a Google Drive repository with working documents so people can get acquainted with your project and decide if they have something useful to contribute. My advice is to use Google Docs + Drive like we do because it allow several people to work on documents simultaneously and there is a small chat attached to them so it can be used for real-time conversations as well.
I have to say that creating working documents for collaborative project is a difficult job in itself because you have to create comprehensive assets and make them short and easy enough to understand (most people will be intimidated by a 100 page worldbuilding bible) so my advice here is to finish your site or repository (I still recommend repository) and share it for public so people will be able to look at your actual working assets.
On to the more practical questions. Since you have decided to be a creative director and whole project will be based on your concepts, what do you have so far in general and how do you expect your potential collaborators to get involved? For example, if you need help with worldbuilding, you have to have some document with basic worldbuilding prerequisites to start from or if you need help with plot points, there must be a general story outline and character sheets to put it all together.