@Nathan Frost typical for Detroit, that's why we offer our clients several security options, including removing & storing mechanicals when vacant and then reinstalling day tenant moves in.What makes you think the seller will install new mechanicals?

If they would consider, what kind of leverage would they offer? 

We offered $75k under asking and they accepted. 

I require tenants to replace consumables like refrigerator filters or HVAC filters.

Right now I am on the middle of a flip no more cash in hand to make an offer so my only option seems to be investors or a HELOC against my flip or my own house.

You may need to call once a month for a year and most times you won't talk about real estate, you offer your help if they need anything.

We made an offer (which was accepted) and ordered a home inspection.

Even if the units you tour aren't the one you eventually buy, walking around the area and getting a feel for the property types will help you be a much more informed consumer when you are ready to pull the trigger. 

I would buy from a brand that is offering 1.9% financing like Hyduai.

A better approach is to network with other experienced passive investors and review the offering together.