Create an IDX to be used in Real Estate sites

Build a Real Estate IDX. This is not something we necessarily want to sell to agents. We are more interested in owning a 100% customizable system to be used in our own sites. Good design is difficult to define because we all have our own ideas. Because of this, we would most likely get our own web designers involved to collaborate on this. We need someone to do the technical programming part. This is easy to define. You can either do it or you can't. Basically, you would need to create a program (an API?) to get (scrape?) information from MLS and display it in a particular order on our website. We must be able to integrate this system totally. Every listing should have a different url. Every page must be indexable on the main domain. Advanced search functions must be created to display criteria from MLS in an order of our choosing. The end result will be a high end IDX more advanced than most that exist now, if not the most advanced. PLEASE ONLY REPLY IF YOU HAVE AN IDEA OF WHAT I'M TALKING ABOUT. PLEASE ONLY REPLY IF YOU ARE FAMILIAR WITH RETS, MLS, AND IDX. Please reply with a general overview of what other team members would be involved, an estimate of cost (although we know this can change as project details become more clear and change), an estimate of time, and questions for us if you have any.