where to scan my negatives in Netherlands?

Hi,
Do you know where is possible to scan 4x5 negatives in Netherlands for reasonable price? I need for offset printing (with 6X enlargement).
I'm in Groningen (sometimes also in Utrecht and Rotterdam), so something close would be great ...
Or, if you know a lab which accepts by post the negatives that would be also good for me.
Thank you very much for your answers in advance,
B

Kleurgamma in Amsterdam, while not convenient, should be able to do it.

If you are in Amsterdam, you can rent time on their Flextights

If you like to communicate with the guy who actually makes the scans for you, i can recommend: www.hansbol.com. He does a lot of work for Nederlands Fotomuseum, Rotterdam. So he will be frequently in Rotterdam.