Even if they stopped reporting your payments the history would be there. 

The time period you select is whatever you are comfortable with.

A question I have is, if i rent out the main unit that has 4BD-2B, is it better to get a long term renter with steady rent payments from them or rent out for airbnb?

They used to be marketed with all of the other homes on the main search page, but a user had to go into the filters and specifically select the "FSBO & Other" tab.

You can also take advantage of lower down payment loan products rather than going 20-25% down on a conventional investment loan. 

Cost Overruns: After the final payment, the contractor claimed there were additional costs of $60K.

An example, a small down payment initially, but the note has now seasoned for 60 months with on time payments documented by a third party servicer.

HI Jewell,If you were to use FHA again, this could trigger the FHA 100 mile rule + 1.75% upfront fee, however with a few exemptions Indeed FHA allows you to put 3.5% down payment to invest in 1-4 units.

Then get photos and get third party verification that everything was done right prior to making your final payment to the contractor.

The limits are not high at first, but they can build with good utilization and payment history.