http://www.emigra.com.hk/hongkong/page76.php
On the other hand, if you can qualify for the Quality Migrant Admission Scheme, you have a year before you need to show them any of the above. But they only let in one batch a year, I think in June.
http://www.immd.gov.hk/ehtml/QMAS.htm
http://en.wikipedia.org/wiki/Quality_Migrant_Admission_Schem...
As for the business climate: if you have a physical product, HK is still the world's greatest gateway to China. If you're developing webapps, the broadband is good here and there's enough coders floating around. Once you're profitable, the immigration department suddenly becomes much nicer to you and will let you sponsor whatever staff you need. Taxes are low and simple (BUT, if you're a US citizen, they're not, because the IRS treats any American who owns a company overseas as a tax evader and demands insane documentation. You will have to understand at minimum the IRS forms 5471 and 8832, or more likely hire a lawyer to understand it for you).
And, a final warning: if you're trying to do anything pertaining to real estate or telecoms (AirBnB, Renthop, etc.), bring a pair of brass balls and a copy of Alice Poon's "Land and the ruling class in Hong Kong", because you're up against monopolists who own the government and all the infrastructure and will use them to crush you: