I am a single family investor looking to make a first multifamily investment in a friend's company where he is the lead GP.

First you need to have extensive experience in deals to understand every risk profile as well as have the connections to find product to buy. 

Considering I currently have bad credit (dropped from a 769 to a formidable score after going in hospital) and no deals I haven't been able to receive the 100% Finanncing products from PMLs.

Multi families are very popular in the area and single family properties that need live are also pretty common.

You can find a single family or multi-family for that price, up to you which you'd rather do.

But the cost of production is regionally fixed.     

If you talk to enough people or the right single person, maybe you want to do what it is they do and you just found yourself a mentor!

For example, when I search for single family homes up to $100k in Pensacola there are only 16 options as of this morning and only 27 if I open up the search to include the surrounding areas. 

The property types that would most be affected are "soft story" dwellings and single families or small multis built on un-reinforced cripple walls.

You can have the house in production while you are working on permitting, site work, and MEP connections.