ASK HN: Sample contract for vested shares for a new cofounder

Hi,

I'm bringing onboard a new cofounder for my startup. After negociations, we decided that he would get a percentage of the company vested of 2 years and be paid a small salary hourly to cover cost of living.

Does anyone know a good sample contract I could use for that? My company has already existed for 1 year and is a offshore LLC (based in HK).

Are their any tax liabilities or other things I should think about?

Thanks