Need an AJAX Live Bus Information Map to be built

I have a client requesting for a map to be developed which when queried to the user's given location (be it Postcode or name of location), the map will then display a number of local bus stops. Clicking on one of the locations displayed would then show a pop-up containing the results of another query for the Live Bus times for that particular stop.

The Bus stop location data and live bus data is drawn from an API, so mostly what needs to be done is assemble a map and the necessary scripts to do the queries. The API isn't CORS enabled, so due to the server setup for our clients, PHP will be required for the server-side scripts to access the API.

A similar system that the client is referencing for this project uses Leaflet.js as the mapping library with jQuery. Though the scripts query an API for the live feed, the location data is held in an SQL database in order to run proximity queries against all the locations.

All the necessary data is at hand. More details will be disclosed once the project is agreed upon. Applicants need to be UK based for this work. The estimate for the time and budget for the work is something that has been calculated on our end, but we are interested in hearing whether this can be done for cheaper or requires more time.