Freelancer for the development of a real-estate site

Background:
The City of New York provides a database of various real estate transactions. The site will allow the user to view the information created on several levels. The levels are from the basic transaction, the neighborhood, the borough and city wide. Through the compilation of the data the user can see the information in numeric and graphic form on various levels. To provide background, the site includes qualitative information and links to outside sources.
The project has several stages. The first takes data from a single database and combines data that is uploaded on a monthly basis via a CSV file. Future extensions of the site will include an API that will allow access to data from various databases. Information about the API will be provided at a later date.
Also, the backend of the site will have to be constructed in such a way that the administrator of the site will be able to upload the CSV file and change the data without the assistance of the developer.

All software developed is and will need to be the exclusive property of the owners of the website and must include all necessary code and detailed documentation.

Site specs/modules:
The owners of the site have an excel file that represents the real estate transactions performed in NYC since 2005. The data needs to be uploaded to the site and displayed in numeric and graphic form based on users requests. The files are assumed to be uploaded after being converted into a CSV file.
The numeric and graphic data presented on the site will be in various mathematical and statistical forms including averages, means and other metrics important to people working in the field of real estate.
The whole idea of the website is to be able to dissect this data and display it to the visitor in a form of a “mini report” based on users requests. To see an example of a proto type we have developed, please visit http://www.empiretrends.com
The site will allow the view of the data on the site on a permission basis. It will also allow users to subscribe for a monthly fee and receive reports via email.

Site flow:
1. The home page will have 5 buttons with the borough name on them (Manhattan, Brooklyn, Bronx, Queens and Staten Island).
2. Those buttons will lead to pages that display a map of the borough with clickable neighborhood links on them. (maps will be supplied)
3. Choosing a neighborhood will trigger a light box form which will specify the options of data to be displayed in form of a report on the next page.
4. Submitting the form will send the visitor to the dynamically created page/mini report. The mini report will include maps imported from Google, neighborhood descriptions, the analyzed data and the ability to view the raw data.
5. The user will be able to change the timeline of the graph based on options presented under each graph. For example, if a user chose to see the data for 12 months running, they will be able to change the presented data by pressing a button under the graph to 24 months running or annual data etc.
6. The included excel file will show an example of the required home page.
7. Each borough is color coded and the colors follow each neighborhood in the borough.

Types of reports and data analysis:
In the first stage of the website there will be 3 types of reports: Multi Family, Commercial and Industrial.
Data should be dissected in the following matter:
• Average Price per sq. feet for the past 12 months running.
• Number (volume) of sales over the past 12 months
• Median Price per sq. feet over the past year
The development needs to allow for future report categories for example residential sale etc.

The Backend:
The backend will be a database using commercial off the shelf software. The database will be changeable and an interface will be developed for basic modifications that can be done directly by the site administrator who expected to have little technical knowledge.
The backend must include an easy-to-use import ability for a file in CSV format.
Additional Modules:
1) a friendly UI that will allow us to upload data monthly
2) ecommerce
3) The site will allow for Google Ad Sense
4) The site should be Google optimized
5) The ability to add future reports and APIs