I took an excel sheet I found online (from "Tactica") and tweaked it a bit to help track and compare different major cities/ different local cities by taking its population growth, labor stats, and rental stats/ multifamily stock to help someone visualize the different places and see where their next investment could be.

The next day he back tracked but I already found another tenant.

Sounds like you're on the right track with your REI journey.

Also, come resale time, the duplex would have a proven track record of producing income and has definable value, whereas a single family home is largely dependent on current market conditions and home buyer emotions and buyer pool at that given time

This is completely different from creating two LLCs, and there are many reasons you might want to avoid the complexities of having dual LLCs, particularly for a smaller asset, like the one described in this thread.  

I am looking for something to track what maintenance happened when, by who, the costs and how it was done.

How can I manage/track payments? 

You and your brothers are on the right track regarding real estate.

Chris I think your on the right track I bet there is something in those reports that is causing this issue ..

What is a simplistic software to assess current property as well as keep track of finances such as profit?