美國green card

you are live in HK now?
if he plan to come to Hk and live with you, he can submit the appliacation from HK.
he need to file a form i-130 and i- 485.
if you born in Hk, that will be about 1 years waitting period to get the marriage visa to go to USA. your green card will then mail to you when you live in US.
i forget the filing fee ( @ $300 or $400+ USD ). he should be ok to file the form himself.
otherwise you need an immigrantion service agent to help you.

should I file the i-130 form thru. (Hong Kong) US Consulate? Are you sure it takes about one year?