Once you have that in mind, you can find from the census data what areas fit your model.

To get access to reliable phone numbers, you're going to need to prove to the data vendors that you're a reputable company and responsible with sensitive data.Alternatively, you can use a service that can get you the numbers you need.

I have the data.

You should start with your own investment goals, then conduct market research and decide on the market that may best meet your needs, then look at listings, once you locate properties, get a rent survey and run a investment analysis using the APOD form (Annual Property Operating Data / free / google it).   

Is that data recorded somewhere other than with the broker? 

Also, limit the  opportunity where someone can can fill in data in areas like Other Contingencies or Other Considerations.  

You can find good data on REALTOR.com as the feed is direct from the MLS.  

It doesn't look like you are running into any issue at this point but an input page would allow you to control your assumptions better and give you additional ways to enter data.

Once I have all of those put together it is very easy to see if the deal makes sense.Once I have all this data I can pretty much see a worst case scenario and a best case scenario.

Historically, appreciation has just matched inflation (see the inflation adjusted long term Case Shiller data).