If you are going to pull a HELOC on property A to acquire property B, and plan on refinancing property B to pay back the HELOC on property A, then you need to somehow add value to property B so that you have cash to pay off the HELOC.

I also noticed the transitions from poorer areas to more B and A class areas.

That very much narrows down the choices for most people.   

You will narrow your market a little bit but plenty of younger guys, working professionals, etc don't cook much anyway....

I would first start with who is closest to you, and then narrow it down to who has similar goals and could handle the financial and time aspect of investing.

It's ripping off the proverbial band-aid, but it's almost guaranteed the inherited tenants will not be willing to pay what the rest of the world would for those units.

You can narrow down the buffet of choices pretty easily by eliminating options that purely just don't fit your strengths, goals or time commitment.

For the fully vacant units we have I have them listed for a group or family that would like 4 b 4 b and they haven't moved. 

Also narrowing down your rehab budget by itemizing and developing a scope of work would help keep your numbers honest. 

Since you are investing OOS as well, just be open minded and narrow down your niche as much as possible.