Here are a couple things to think about. How will you get funding to buy the properties and then funding to fix them up? If you rent you need enough cash flow to maintain the property. In a "not the best area" people tend to no care about the property they rent and give you more problems paying rent, in general. If the area is not great you would have to get the house extremely cheap and be able to fix for under what the market value is in the are to make any income to keep moving on. This is very difficult in these areas simply because people wont pay a decent price for a nicer home in an undesirable area. These are just some things to think about.
It has been tried in my area and the non profit didn't last a year. They bought 2 homes and didn't finish rehabbing the first home, it was eventually demolished after they invested money into trying to fix it up.
I would say your best bet would be to fix up hold and rent if you go this route.