If your search here is unfruitful, then i suggest you try on upwork (give it a search) and be as specific as you can with the specs, this will help your developer a lot and hopefully cut down on your costs in the end, assuming an hourly salary is agreed upon.

I have no doubt you can find someone with the necessary skills, only question is if you can afford it.

Not sure a stake/part in a company will get much interest, if even allowed.