I'm oriented on evaluate Selenium WebDriver (or other similar tools, suggestion? ...): are there somewhere examples / tutorials / experiences or similar?
Looking at the examples at their sites, I think using Selenium might be hard since the maps are rendered in images. Maybe a image based testing tool like Sikuli is worth trying.
We have build a GIS system based on the Google Maps API in the past and we did successful test this with Selenium, but as Google uses canvas this was also not easy and straight forward and often resulted in brittle tests.
Try to get in contact with the developers (on GitHub) of these libraries and post some questions there how they would do end-2-end testing of their implemented framework for a client.
I would also have a look how these libraries are testing them selves