@Michael P.
You need to figure out your goals and your risk tolerance... You could do flips or rentals. You could go Single family, or multifamily. You could go low income or bread and butter...
I own a property management company here in Indianapolis. I designed our systems around finding good tenants for low income houses. I manage rentals from $450 - $1900 a month. I have just as many bad tenants in high income houses as I do the low end ones. High end tenants are so whiney. "My LEFT shower door doesn't work.. Come fix it!" "I pay a lot of money to have a shower door that works, so you get your butt out here to fix it.. NOW..." Recently had a guy complain because there was three wire brad-sized nail holes above the fireplace... Seriously?!?
As others have said you will have a hard time cash out refi'ing the lower income stuff.
Just really depends on what you want to do. I prefer to have 2-3 lower end rentals to the 1 bread and butter, but that's just me.