Google Maps API / PHP / SQL

I am launching a site in june and we are looking to add some mapping/search functionality. What we need is the ability to draw polylines in google maps to create several boundaries and then the ability to search within these boundaries - so it would have to calculate the post codes or locations within the boundaries, search the database and bring back results accordingly.

Say for example I drew 2 boundaries of 10 connected polylines and I wanted to search for shops (from our database) within that area and bring back the results.

This would need to be integrated into an existing site and would need to be completed at a high level. I am looking for someone who is very comfortable with Google Maps API and can work their way round php, SQL search functionality with ease.