You are welcome Zain,
As you are already in Singapore, it will be a good idea to talk to some local certified professionals (accountants and lawyers). While it would be very tempting to incorporate there, it will give you the highest setup and maintenance costs. You will be paying up to 17% corporate tax plus 20% tax on each partner.
Setting up in Hong Kong means that your company pays zero to Hong Kong, zero to Singapore and zero to the US if you are paying yourself less than $103,900. You will have to file and send reports to both Hong Kong and US yearly regardless of how much you make.
Where you earn/pay yourself more than $103,900 the “stacking rule” comes into play. $103,900 will be subtracted from the total amount earned and you will be taxed on the balance but at the rate of the full amount earned. There is the opportunity for you to subtract some deductibles as is your right (especially if you have kids), for this reason I strongly advise you talking to a US certified tax lawyer.
The above link is for a company in Hong Kong I am interested in using but have not used them yet. They can assist you in the company formation, accounting & auditing, tax filing and Company Secretary. The cost for a Hong Kong company setup starts from $399. There are a number of such companies in Hong Kong, please research a few before picking one. The setup should take about an hour and you will only need to visit Hong Kong if you decide to open a bank account there for your new company. I would advise you to do this even if you plan on having an account or two in Singapore. In fact, if you can afford the minimum deposit, I would advise opening more than one account.