That said, we start safe and will gradually extend leverage as our personal portfolio grows...again, I know the math works and help investors all day long; but at the end of the day it's YOM (your own money) and therefore must be measured against your or risk-meter, to use Ramsey's words.  

Cash flow is literally the last realization and area of importance, so cap rate for that is going to be a harder measure apples to apples with equities. 

The calculation is the monthly rental income divided by the monthly debt (interest, principal, taxes, insurance, and HOA if applicable) It is a quick and easy benchmark used in the measurement of an entity's ability to produce enough cash to cover its debt payments. 

I agree with @Kevin Sobilo with some additional thoughts from my experience thrown in for good measure. 

Stessa imposes no fees for either landlords or tenants to use online rent collection, and it offers strong security measures to protect both parties’ personal and financial information.

What does the sufficiency test measure?

The problem is there is not a lot  of inventory ( small multifamily homes) in my area. im looking for advice on what measures i should take to take the leap if i don't have anything t work with. 

Once you're clear on that, I would make a 5 year vision, and then you can start writing down SMART (specific, measurable, achievable, relevant, time-bound) goals as milestones to help you get to that vision. 

I agree with Micheal in terms of calculating your cap-ex, reserves, and property expenses (excluding mortgage and insurance) to measure your ROI against your goals. 

I'm not concerned about Innago's security measures.