I am looking to target younger families, single family homes to start.

(Note: you said "single" which you are not.

We're now dancing around the 6000 total single family homes available which swings up as the weekends approach and new homes hit the market and retract below 6000 homes after the weekend and homes go under contract.There was a 3.2% increase in active listings from August to September, slightly lower than the June to July increase.

However, there are plenty of charming single story one bedroom house ideas out there.

I include every single thing, however small it may seem...3) Do not try and save by buying materials yourself.

I'd love to hear some experiences on Sherman or even Mckinney with long-term single family rentals. 

Buy the single family first and see if owner will wait six months for the 9 unit. 

I will look at a few factors, rent for area, total mortgage payment with property taxes( which can be crazy in Detroit), investment in neighborhood, I like looking into places where they are building homes and apartments that attract young professionals or families , and also looking at potential to make a single family home into a duplex or something can add an adu or transform a basement to a studio apartment!

With the 8 multifamily units, there is 1 single family house on the lot as well that I am buying with the deal.

If you live in the illegal apartment, and it's separate, then what you've done is use an R-1 (single family home) zoning as an R-2 (duplex), and since that wouldn't be legal, the tenant may be able to successfully sue you for renting an illegal unit - even if you are in the illegal apartment - just because it's not legal to have 2 separate apartments on that property.I'm wondering if you could somehow rent it as a roommate situation, though, and get around that.