Hello,
I have built a similar API that integrated data from Google Places and Factual API.
I have worked with various mapping platforms (Google, Here, OSM), QGIS, PostGIS, Google Earth.
I'm also an experienced Python developer and Linux user.
For this project I would build a Python application based on Tornado (because it is fast and lightweight), Postgres (if a local cache is desired).
Best wishes,
iticus