Let's pin the place to make a group booking, getting a decent list of alternatives for Summit participamts while we find it.

One candidate I found after 10 minutes:

Ibis Amsterdam City West
Room for 1 to 2 persons: 62.33 EUR / day. Breakfast extra: 15.00 EUR / day / person.
2km of nice walk through the park. Public transport to be seen.

BEAT THIS OFFER!

http://www.accorhotels.com/gb/home/index.shtml might be a good place to find alternatives.