it's good that you have a good credit history and $80,000 as your personal income. But 6-family house is a commercial real estate property and even you are willing to occupy one or 2 apartments for yourself you can't buy it with 10% down payment. Commercial Banks on today's environmental are very conservative based on your past real estate experience (I expect you have not owned such type of real estate in past). Loan amount is based on current appraisal value or contract price what ever is less, what cash flow is generated and expences (property tax, insurance, market vacancy in the area, expences for heat, electric, maintenance, replacement reserve for the roof, plumbing, outside frontage, boiler and water heaters, etc). So based on what I just stated you will need to come up for at least 25% down payment.
Sorry for such response but it's a real picture today.