These would be questions for your lender. They will review income/assets, etc. and apply certain formulas. Particularly in a multi-family were rental is factored in, there are formulas for how that rental income is applied. You are asking all the right questions, and your loan officer will answer them in a way that is tailor-made to your individual situation.
Typically if you are going to live in one of the units, and underwriter can consider lease payments on the other 2 units towards qualifying. It's best if the other units are already leased out. If not, then they need to go by market level rates.
The FHA jumbo mortgage limit for 3 unit homes in Queens County is $1,129,250. The down payment required is only 3.5%. The rate for this is going to be good, but PMI on FHA loans is killer though. On a $990,000 loan your monthly PMI would be $1237.50 on top of the monthly cost of your mortgage and any property taxes and insurance.
The Conforming jumbo loan limit in Queens county is $967,950. The minimum down payment required on a 3 unit owner-occupied home is 25%. And you will need at least a 720 credit score for all borrowers.
As far as HDFC goes, that is probably a no. Any co-op, condo-type building you purchase must be Fannie Mae or FHA-approved.
If you would like to talk in further detail and see what you can qualify for, please feel free to give me a call or email me and I can walk you through things.
Loan Officer -NMLS #977416
WCS Lending, LLC
Toll Free: 866.936.5363 ext. 278