I want to be able to find potential markets/listings nationally based on the return. 

Aims for a balance between cash flow and potential appreciation. 

Keep track of 3 buckets.1) Owner occupied portion - potential deductions for schedule A2) Tenant occupied portion - potential deductions for schedule E3) Jointly occupied portion - likely prorated for both schedules.There are nuances to this, so I recommend looking for a tax pro who can coach you on this. 

I'm looking at purchasing a small multi-family rental property in the Allentown or Philadelphia area, and I plan to use the BRRRR strategy.I'm struggling with the best way to analyze potential properties to ensure a solid ARV and would love any advice on effective tools or methods you use.

The terms may be more favorable, if you are just starting out a bank maybe nervous to do 3 at once, therefore their perceived risk will likely be reflected in less favorable terms.     

Go places where you can connect with potential buyers and sellers. 

Jumping into REI with no capital is not worth the risk.

I was reading up about it, and saw that the cons of oil heating include needing to top up the oil supply, lower efficiency (than gas and electric), and potential leaking of tanks leading to environmental issues.Is anyone familiar with oil heated homes?

I am interested in this given the potential for big equity.

The BRRRR method (Buy, Rehab, Rent, Refinance, Repeat) could also be a great strategy to recycle your capital.To find deals, try direct mail campaigns targeting absentee owners or distressed properties, or go driving for dollars in neighborhoods with strong rental potential.