how to find a software engineer in china?

Dear all,

I am inspired to open a small business developing a specialized small software application. I have good confidence that this tool has nice market. What currently bothers me is how to proceed in the software implementation. I basically have two choices:

(1) find a partner in bay area who is a software engineer and can do the job. We share business equity if any.
(2) outsource it to china. Pay a developer or a small company in china to get it done.

I will design the software in great details. All I need is someone who can execute my design and provide suggestions in very low level software implementation which i have little knowledge about.
My intention is to hire someone in china to get it done full time in 6-12 months. The problem with hiring someone in china is the maintenance of the tool. In the future, the tool will surely keep updated according to clients’ ever-changing business needs. Then i have to beg the developer in china all the time? Alternatively, if the documentation is clear and full, i can hire someone here to work for me if my business does make money. I am being hopeful in this matter. Veteran business owner please advise me how feasible my hope is.
Furthermore, what do I expect to pay a software developer in china with a bachelor or master degree from a reputed university with 5 years relevant experience? do I need to withhold US tax? how can i pay the tax in china? can i just send the money to the developer and let him/her worry about the tax in china? thanks a lot for your advices. The first step is always hard. that is why i am coming here to learn and for help.
There are many advantage of finding a partner nearby in bay area. However, I am not that confident I can find someone reliable as a business partner. I do not know anyone in software industry personally. Furthermore, everyone is busy here. Even if I find one, the partner may have very limited time working on the project outside of a full time job and family obligations.

Thanks you all for the suggestions.