I mostly want to buy a duplex in a way where if tenants leave I won't get stuck paying to store or dispose of their stuff.

He actually suggested I demolish it and start fresh for $350k new building.... lol.

The south side of Chicago is where your money will stretch the most, and some areas are great investments while some right next store not so much so you really have to do your research on the neighborhoods as much as the buildings.

But, like I'm sure you others will reply as well, you are better off to start off fresh with these vacancies as inherited tenants can be a huge pain in the butt. 

It's going to need heavy duty cleaning, fresh paint and carpets when they move out. 

you can go to job sites of new builds and get some cull lumber , you can pick up some deals at the Habitat for humanity type stores.

Maybe call Home Depot and ask the store manager.

Does your mark a call for it to be completely renovated with granite countertops or are you in a area where from make a countertops and big box store cabinets are the norm.

Often, it isn't real great - it's like a store credit card with high interest - but it might help spread out the cost a little. 

Cities and towns sometimes use "commercial" for not only store fronts, industrial, etc. but also a certain # of residential units and higher.Real estate agents and appraisers usually reserve "commercial" for office/retail/industrial, basically not residential as we normally think of it.But "commercial" in the mortgage space means a certain kind of loan (e.g., adjusting every 5 years, maybe a shorter amortization and/or balloon payment), and the mortgage may or may not be secured by a residential property.So there's unfortunately no real standard for the terms.