We have thought about selling our home buying a duplex and renting the other side.

In my opinion, it's better to make mistakes starting out on duplexes and 4 units than buying a 20-unit after saving up a bunch of money and making a lot of mistakes because you have no operational experience since it's your first one. 

I'm exploring all options at this point including finishing the home with other builders, as well as selling what has been built (slab and block walls of a single family home 4 bed 3 bath) to another builder or investor.Does anyone have any recommendations on where to look for potential buyers for something like this?

We fell in and out of a deal for a single duplex in the spring, but kept searching.

I'm not really sure why you are responding to my comment with this wall of text that at first glance appears to refute my position that GP's are to blame, but does not actually provide any argument.

Best I know, Milwaukee has 66,000 duplexes, which is more than any other city in the US including Chicago.

20-25% down, duplex, break even on cashflow in a promising area.

The house, turned duplex, was gorgeous.

I'm looking at house hacking a duplex or the like for my first investment property and looking for some advise on timing.

I did this exact thing last time a tenant asked to install a TV mount on the wall of a bedroom.