Sounds like a great project! You've obviously put a lot of thought into the characters and story so far.
While I can't help myself, I noticed that's it's not entirely clear what you actually want 
Like are you after just one artist or a team, do you want writers as well? does the work involve character design or worldbuilding, or just drawing pages of comic from references you already have? Is the story fixed already or still open to discussions about scenes and shots etc? Is the entire story written already?
It's good to be clear about expectations, especially as your project is technically unpaid, pending funding. So I think anyone joining would want to know what's expected of them so there's no surprises "I thought you had character references already!" sort of thing.
I think it's also good to be clear about how the revenue will be split so there's no money problems either. i.e. will it be split evenly between all project members? or based on the amount of work they do?
I also think that your estimation for producing a volume (assuming we're talking about a ~150 page book) might be a little optimistic as well, especially since revenue won't come straight away (probably), artists still have to pay their bills in the meantime and so can't invest a lot of time without getting something back in the short term as well.
All the best 
All excellent questions and thank you for the input.
As far as building a team I am just looking for individuals who are inspired to help in this project. Whether it is just one person or ends up being multiple I would want to bind the collaboration with a solid contract that would 100% ensure they get in return what they are dishing out for my sake. Character design and worldbuilding will be essential in this project. However, seeing as I already have a written illustration for the characters, creatures, and locations we won't need to spend too much time trying to figure much out.

The story for the first volume is already planned out but I do want those who are willing to sacrifice upfront payment for a rev-share opportunity to feel as if they were duly credited for all of their work. So, I would want to hear from every one of my team members how we can make this manga the best it can be and I plan to take everyone's thoughts and ideas into discussion and confirm which ones work best for everyone. Although, I only plan on releasing the first chapter of volume one out to the public as a way of introducing the manga and possibly receiving revenue from the sources I mentioned above.

If the manga fails in positive statistics that would prove a favorite to many then any proceeds we did make will go directly to the team involved in the development of the first chapter. From there, I will take time to perform a reanalysis of the statistics of the first chapter and research the reason behind the failure. Since I am only expecting one chapter be completed in collaboration with artists and writers it won't be as much of a wasted effort and time as it would be if we released an entire volume and the whole thing bombed.

As far as payment goes, once we do start bringing in revenue, it will all be based off of the artists/writers usual payment expectations. What I would normally pay you in full for your work will determine the percentage break-up between you and the others. So, if a sketch artist would normally charge $100 per page and an inking artist would charge $75 per page then the revenue from merch sales, donations, etc would be divided out so that the sketch artist would receive a fraction more than the inking artist since their base cost is, ultimately, higher. However, this is all up for discussion if enough artists/writers who join have concerns or dislike that compromise.
In concern to the amount of time set for completion of this project, it is for the first chapter alone and not the entire volume. I see where you may have assumed that and I apologize for the lack of details on my part in my post.
Any other questions?