customization of google map display

We are displaying a google map on one of our web page. Nothing special, the usual google map stuff. The map is centered on Belgium. We would like to 'erase' the eighbouring countries and display the Belgian map alone while preserving the usual google features (zooming, clickable markers, etc). We believe this can be achieved by adding white polygons on the map, to match the external Belgian state borders and hide the neighbouring countries. We are looking for a freelancer with exprience in this field. Please provide relevant references if you decide to quote for this job. Thank you for your attention.