In addition to keyword alerts for BP I also have criteria alerts on Redfin to see when properties are listed that fit my desired criteria, which is still just for research and info as I don't yet have the capital to jump on them.

I am trying to build application to pull property information and make decisions based on the data available for the house, neighborhood, properties sold around the same are ect….What is the best fit company/API which can provide API data (XML/Jason) which does the following?

I always have multiple exit strategies, then fit one to the deal.  

There are people fitting your desire although might be tough limiting yourself to just the D.C. area. 

Lots of great opportunity in Palm Beach County and I would be glad to help find an investment that fits your criteria.Look forward to hearing from you.

I personally wouldn't excluded houses that fit my other criteria if my unit "costs" money to live in it.

i get properties in San Francisco, greater bay area and mostly sacramento . if they don't fit my criteria I usually wholesale them to other investors.

So that is something you always want to consider- what market will best fit your goals, rather than just hearing a particular market is amazing and going for it.

Now hear me out for a moment...I have often made the analogy with wholesaling and fitness.

I will not improve unles it fits my plans but I am required to keep it the same.