How to turn an owner finance deal into a 30 year rental loan without 20 percent down?

[Christopher Robert Noland]

Say I can get an owner finance on a 99k house for 5 years with a balloon payment. $2500 down. 

Then rent it out. Investment only. 

How does one take the owner finance situation to a bank and turn it into a 30 year loan to hold without an additional down payment of 20 percent ? We are not flipping the house are are just trying to acquire it. 

What type of loan and lender would allow that ? I know someone who does this but they won’t give up the secret.