From reading her posts, I'd bet @Helen Kirk has some insight on this....

Ziaur,There are lots of lenders who can get you 1-4 units with 30% down, we can help you with the financing, also out of state you can get more bang for your bucks, your best bet would be buy 5 properties for about $40k each and get rent of about $850 each, that should put you at the ROI you are looking at. 

Your best bet is used transactional funding.

If the quotes are similar you will be in a strong position, if they are widely off you might be safer if you err to the high side.

But even then I bet I could negotiate upfront my required schedule or they get terminated.

The knob and tube wiring hopefully can be replaced soon, your best bet is to get quotes for the work 

I just BET you would attract the attention of a big thinking friend who would share knowledge with you.

I would bet the selling price of a Duplex would far exceed the price of a SFH especially if it's in a SFH neighborhood.I wouldn't be to anxious to convert back to a SFH.You could have a POT of GOLD

This is precisely why I believe online applications are a much safer alternative to paper applications.

Chances are it won't.Now, if you are looking to broker deals, or need the license to do (or make it safer to do) wholesale work (like FL) AND you can make some money at it brokering deals, that's a different ball of wax.