If it is up here, drop a comment and I can more specifically share and give insights.

@Luke Morris TamneyI would open a high-interest savings or money market account, specifically for real estate investing, and save it there.

While I wouldn't call it "big boys" - there is a very small world of professional companies dedicated to this super small specific asset class. 

A lot of times, these types of lifestyle choices will start limiting you down very quickly to specific areas, and since you are going to be living in the property, are likely to have a heavy weight on the neighborhoods.  

We're just using the Illinois lease that BP puts out (https://app.box.com/s/r0b3spxpse7jc0qe42tz95f056yand9h), but I can't find any specific penalties for early termination in there.

If you have any specific questions or need guidance along the way, feel free to reach out.

While they are not specifically midterm rental leases, they are specific leases for people that are staying 30+ days and that is what you really care about. 

Go put your 600k in to a short term treasure bill and collect your 5% until you have educated yourself enough to know exactly what,where, and why a piece of real estate works for your specific situation.

Tucson Section 8 is valuing my two- and three-bedroom units in a duplex well below market rental rates because they said they don't have data supporting higher rents specific to duplexes (they won't compare to SFHs or Apartments).   

They didn't specify specifics, but they said that they will work out a new rent schedule to account for the transfer of costs from yourself to them for heating and cooling.Incidently, they were trying out these new window heat pumps that look like a horseshoe.