I have a multi-unit apartment building with a 218k possitive cash flow before debt service but after expenses. If I give the owner a note for 300,000 for the deposit, will I be able to get a bank or money lender institution to lend me the balance of 1,150,000? I can put up collataral for the 300,000.

It depends on the property being able to repay both loans.

It depends on finding a lender that is comfortable with you not putting any money down. I have only seen one deal like that in nine years in the banking industry, and the loan was guaranteed by the seller.

It depends on the appraised value.

It depends on the additional collateral.

Unless you go with private financing, you will not be getting into a commercial property with anything less than 10% down. There are stated programs but when you cross the $900K mark all commercial deal are pretty much full doc. The building will have to have at least 1.2 debt service (which can usually be manipulated based on the terms of a seller 2nd).