Clickable & zoomable map

Client has a drupal database that stores retail vendor information, locations, contact, etc. It needs additional columns to store a product type flag, latitude, & longitude. A zoomable, clickable map needs to be built that will be used to establish the viewer's location (latitude/longitude.) Viewer will use a pulldown to enter maximum distance radius from vendor. Search function will then return those vendors within the stated search distance. We will be migrating the site to Wordpress but will do one of the following: Leave the mapping functions within Drupal Move the mapping functions to Wordpress Move the mapping functions to a stand-alone app using CMS builder for database access for the client. Move the mapping functions to a stand-alone app using Drupal for database access for the client, and repairing some drupal issues. Clean, well commented code is required. Good and thorough communication with me is essential. Do not bid if you are not English proficient.