Hi, I read the description, I think I am the person you need.
I am expert in circuit design/pcb layout/firmware program. I have more 19 years experience. I have designed a lot of products, some of these is used in China High-Speed rail system.
I known how to design a better product.
Please contact me, thanks.
btw, I can find the cheapest supplies & manufacturers when you in mass-products, because I am Chinese and live in China.