The number of homes like that in Detroit are obviously large. To my knowledge, there just aren't a lot of those type of homes in the suburbs. The one investor I deal with does receive a scattering of homes like that, but they are few and far between.
He just received a package of 15 homes that were scattered through the Waterford, Commerce, Allen Park, Oak Park, Southfield, Madison Heights, etc. But to receive a number of homes in a specific city like JUST Farmington, or JUST Walled Lake, I have yet to see that, because they just don't exist in quantity.
Homes like that in Detroit are abundant, for now. The two main guys I deal with just received 300 Detroit homes that you speak about and are rehabbing them. If you truly are interested in the suburbs, your only shot at what you want would probably be the County Tax sale. It is there that you MAY be able to buy mulitple properties in a city.
I say MAY because a lot of the cities nowadays are buying their own foreclosures and then selling them. A lot of the cities have First Right Of Refusal on purchasing their own foreclosures so you may not even have a shot at them.
We have been getting a lot of small lists of homes from different funds that have properties as assets and want to unload them. But like I said, the suburbs are few and far between. The suburbs are more for onesies and twosies.