Interest rates atm seem quite high so will ride this out a bit longer (and ratios will continue to improve over time.) 

You could do the upgrades then rent out the units or sell after you made the improvements.

Plan to make some tenant improvements to push rents closer to market rate for the area.

This type of loan can be a great short-term solution to help you acquire and improve the property before refinancing into a long-term loan or selling it for profit.

Pick one that is improving, homes being renovated and flipped, vacant storefronts being turned into cool coffee shops etc.Good luck.

I would purchase a duplex (or even better, purchase a SFH with as many bedrooms as you can afford and rent by the room), and then slowly improve the property. 

.- After closing, you can do some of the work yourself to save money, but the program doesn't allow you to pay yourself.You will want to buy a Class B property, maybe Class C+, in an area that seems to be improving.

The key is to pick a lane—focus on improving as an investor, finding great deals, and letting a solid property manager handle the operations.

Focus on optimizing the current fourplexes (improving rents, reducing expenses).

That profit will increase over time and improve your return.