If it's really something special as you claim it to be, I would suggest that you get a patent on it if you haven't done so already. It will help protect you and your invention later on if anyone tries to steal it.
There are definitely manufacturers out there that can help you build prototypes. Those are usually specific businesses that specializes in building prototypes and do not actually mass produce products.
First, get a patent if you haven't yet. Second, find a business that will help you build a prototype. Talk to them first and see what they can do, the services that they provide and how much it will cost. Don't just ask one business, but shop around and check other businesses to see who can give you the best deal. After that, take your invention and pitch it to whomever you think will help.
Good luck with everything, hope that helps.