What program can I use to create my own regions on a map

Question

I'm looking for a good program to create maps (specifically of the netherlands) where I can specify my own region-borders. For example, in The Netherlands I have many maps that I can use with province / county layout. However, my company has their own division of regions, and I would like to create a map with my own borders. For example outline a region with 3 cities that fall under it. Then I'd like to show statistics/numbers on these maps.

Currently working with R, but haven't found a way to make it possible. Does anyone have any recommendations for programs that allow me to do this? (doesn't have to be free).

For example; would like to be able to make maps like this, but with (handmade) different borders:

Thanks in advance for the suggestions!