I am absolute for an outdoor!! (who didn't allready guessed?

)
Anyway....
Locations are always booked long in advance, so we have to plan quickly. As i've said, i've done it before. Biggest event was for 300 people in Arhem and some 30-80man event troughout the netherlands. So an outdoor event for us should be a piece of spacecake.
I hope you don't mind me jumping straight to the point now.
First 2 major things i've need to know are:
Around which date? A midsummer date was mentioned, but i need something to work with. Don't expect much locations to be free that weekend, so i need more options. or Timespands rather (1 week before and after to play around with).
Also i need to know an area where we want to stay... Utrecht/Eindhoven/Amsterdam? Or if you know a place allready, just PM me.
Also think of our belgium friends or maybe german who might want to attend.
I'll try to keep costs as low as i can possibly do, but I expect to bring your own drinks/food..............or someone else makes arrangements for that..vollunteers?
a small core-team would be best for this whole event btw
EDIT: unless it turn out to be less then 15 to come offcourse