How to establish production in China?

I came up with an inexpensive and very necessary (albeit niche) device - a variation on the theme of a USB keyboard.
I have a three-dimensional model built in AutoCAD, renders and a description of what I want to get. The small thing is to turn the model into a thousand ready-made devices in beautiful boxes.

If you have been involved in any way with outsourcing the production of machinery in China, please share your experience. I am interested in all stages, from finding a factory ( there are thousands of them on alibaba.com ) to obtaining certificates and delivery.

Thanks in advance. I believe that it is not necessary to be Artemy L. to release the device of your dreams.

UPD: The target audience is not IT people. Do not wait yet yet another happy hacking keyboard.