6.5% is def. super good number as it's below conventional.

We had bought the condo with a conventional mortgage in our individual names.

Alternative way could be purchasing this property with normal conventional rehab loan, which is a standard 30 year fixed loan + rehab funds being funded up to 95% LTV.

If you add 2 ADUs traditional conventional F/F is typically not available but in this case the 2 units makes 5 unit.  5 unit s commercial MF with different rules and means to value.

In the ten-year period beginning with Q2 2014, the South Bay submarket has experienced the greatest introduction of new inventory, 8.3 million square feet, amounting to 27.8% of all new competitive stock added to the market.Asking and Effective RentDuring May, asking rents built upon April's 0.2% decrease, declining by an additional 0.2% to $12.82.

If you have the income to support DTI requirements, Conventional investment products will provide the best deals.

With conventional financing, your income, DTI and employment history will be used to qualify you.

I have off market investment property inventory here in Florida.

Assuming the buyer can qualify for conventional financing and your numbers are accurate (which I suspect if I was purchasing my value add cost would be higher)  They purchase at $400k.  

This is a great time to look into the New York multi family market.Brooklyn has seen the highest percentage increase in inventory (74%) compared to other NYC metro area counties since last year (source: oneKey MLS).