I do a pre-screen, the based on that I offer an appointment.

As an example, no jurisdiction can demand a minimum lot size, limit your max size below 850sf, or limit the square footage beyond the states laws, etc.

Their sq ft and size/quality are comparable to the duplex. 

@Nina TelthorstThat's very true.Properties have to be comp'd against "like" properties that are similar in style, size and utility AND that have closed in the last 6 months or so to have an accurate picture of value. 

We don’t know any PMCs to recommend in the area mentioned, but since selecting the wrong PMC is usually more harmful than selecting a bad tenant, you might want to read our series about “How to Screen a PMC Better than a Tenant”:https://www.biggerpockets.com/member-blogs/3094/91877-how-to-screen-a-pmc-better-than-a-tenant-part-1-services-and-processesWe recommend you get management contracts from several PMCs and compare the services they cover and, more importantly, what they each DO NOT cover.

In more detail, this would be my advice, based on what friends have done:  Buy a house with a lot of bedrooms and bathrooms for its price with a walk-out basement; have other people (usually servicemembers) as roommates, renting by the room; house-hack the basement into another unit, and as long as you don't install a stove you stay legal where you aren't allowed to subdivide but you can still have a large toaster oven, a hot plate, and a full sized fridge; then you have two complete units (local-style) when you are deployed elsewhere that will result in a decent positive cashflow and, if you bought in the right place, probably appreciation; cash out whenever the market surges and invest in somewhere that cashflows better with all your profits.  

Basically, working with me to fill the units, screen tenants, coordinate with contractors and other repair or service technicians and be my boots on the ground so to speak.

It may impact your reserve requirement, but it will eliminate the risk of taking on a Tenant that someone else places without your proper screening.

Frequently people screw in the wrong size fuse and that can result in the fuse not popping in an overload and that is one of the reasons breakers are a better option.  

Cost currently are crazy high in most places and given the size of your estimate, as 20% change would have dire consequences ($36k swing is alot of cash).