Hi, Matt S Rinc here and I can (re)create your map, doing visualizations last three years.
The proposal is stated in milestones. The code to read your data should be discussed with you (D3.js expects CSV or JSON file, preferrably, so at least there should be a way to get your data with PHP code into usable javascript arrays for D3.js).
Other requirements are understood. I have one other D3.js active project but can deliver your solution in a week.
Best Regards,
Matt