Hello,
I'm Konstantin, an expert in Lean Development development. Falling asleep, I embrace the book by Eric Ries. After checking your samples, Zillow and Trulia, I suggest you to define the vision - test customer acquisition (includes Landing+Traffic+measure)
and as well - a test of your value proposition (includes MVP + billing + mixpanel)
As for your google maps search interface, we will use PHP (Yii)+JS (Backbone), Sphinx. About quote - to test your customer acquisition - around 2 weeks and one grand (includes Traffic cost) and for MVP - around month and 5 grands (depends on your requirements)
In order to give your ideas the best chance of succeeding, we always use the Lean Development methodology, which essentially means that we define a hypothesis, get timely feedback and test it on the real market, after which we pivot until we find traction.
Please, ping me to arrange the meeting and discuss in detail how to improve your search.
Regards,
Konstantin