I'm holding off booking the ferry today, as a few more options have been suggested.
If anyone else has some good ideas on how to best get two cars, a large trailer and eight people from south east England to Holland please let me know.
At the moment I'm looking at pricing for the following;
Harwich - Hook of Holland ( bit pricey, no return trip available on the Sunday night)
Dover - Dunkirk ( places filling up fast)
Dover - Calais
Ramsgate - Ostend
Eurotunnel
Ideally I would prefer a longer sea crossing and shorter road route, but beggars can't be choosers - plus the cost is always a consideration.