REI Nation manages 7,964 single-family rental homes in 13 U.S. markets, including Memphis, Dallas, Houston, Little Rock, Oklahoma City, and Birmingham. 

I am having to replace the Truss and roof over the garage (garage is attached to the house).

I am leaning towards demolishing the house and building a simple 3/2 but I have no market data in the city for new builds in recent years.

These programs often offer their own lenders, managers, builders, etc, most of which range from poor at their jobs, to completely shady.

So I like to lean into a combination of house hacking and value add.

Does your local housing authority allow this type of arrangement? 

I split my house up into three units.

OldFo is now our house well. 

If the agent is suggesting to put it in writing it might be because he can now nudge the seller into accepting a lower than previous offer since the house has been on the market for a long time with no other potential buyers. 

The biggest thing you'd have to manage after purchasing the right deal for you would be the property manager, so you can make sure he's managing your property how you'd like.