However, tenant's credit history will take a dive and be on record and since I'm the property manager (me / owner), I will not vouch for tenant when seeking for a place to rent in the future.If I go with option "b" and the tenant / tenant attorney agrees and signs an agreement to make it official , at least I can get back my money within 10-15 years.

What should be my next step to narrow down and research?

Do I want something a bit more active or passive (how much time do I want to spend on this property or property project) That should start help you narrowing things down a little and once you're clear on all of that you'll have different criteria to overlay on when looking at deals in Perth/Melb/USA to fitCheers

In the past when I am looking for a property manager I google to find all managers with physical offices in close proximity to my properties to narrow my search and ignore all sponsored adds that fake that they are local.Since you have self managed, you will be better equipped to "manage the manager".

@Jordab Ohana Can you narrow down the type of commercial leasing that interests you? 

My wife has been handling all the complaints that we are filing with the DA, etc.If nothing else we should all band together and file separate complaints to whoever may help us. 

@Aaron Raffaelli we call all the cities that touch Detroit, the Ring Cities - except the Grosse Pts.These cities are mostly Class B and are solid rentals.Detroit overall has gentrified to Class C, but at least a third of the city is Class D still.Check out the interactive map on our website and watch for whats coming...

The lifestyle question is one that you must determine, then narrow down what parts of Chicago provide you with that lifestyle, then we can really answer the question- How is the market doing in those specific neighborhoods?

From my experience, here are a few property management companies that my clients have worked with:ERA Solutions: They have a strong presence in C-class neighborhoods.Realize Property Management: Better suited for A and B-class neighborhoods, though they do manage some C-class properties.Ohio Elite Management: Primarily focuses on B and C-class neighborhoods.

We follow a similar model as @Bill B. and with similar results, except our properties are from the 60s, so we gut them and rehab from the studs up, basically resetting the clock.