Spending on expensive upgrades is not the answer to improve your tenant base in this type of area.Keep the homes habitable, clean, and safe. 

Based on what I'm reading here I would focus more on Airbnb/Vrbo.

These loans are short-term, asset-based, and designed for situations like yours.

For example, you could create a weighted structure where a percentage of profits is based on cash contributions, and another portion compensates for rehab or management efforts.Rent Payments and Tax-Free Profits:If you structure it as an owner-occupied property, the rent you pay could be shared proportionally, but tax-free gains on resale may only apply to your share, as you’d be the owner-occupant.

How to Price the Condos: Do a reverse amortization schedule for a 30-year mortgage based on Room Rental Prices in the Area.

That said, I am thinking about Wake Forest, Garner, Apex as frontrunners based on the fact that they are closer to RTP and have generally good schools.

Based on the questions you are asking I think you need to spend more time listening to podcasts like Bigger Pockets and Bigger Pockets Rookie.

Typically, 8- 12% net for OOS investors based on cash purchases.Good luck 

Is  this based on one of BP's deal analyzers?

"^ Do you feel like income you make on the units is based more off of square footage or location rather than add-ons you made for you while living there?