Well a loooong time ago (1990), my brother and I went six weeks and 1100 miles of sail camping around the Baja penninsula: http://www.hobiehawk.com/BajaAdv.html
We used some rather large custom made dry bags that literally took up the front half of the trampoline. They had a zip-lock type seal and then you rolled the top a few times. Keep in mind we had an 18 with wings, so we had someplace to sit, otherwise it would have been terrible.
That was for 6 weeks, for one week you should be able to find (non-custom) dry bags to accomodate your supplies, clothes etc.
Keep in mind that if you flip, you wand to be able to somehow get at your stuff to untie it (if needed) so you can right the boat.
I would NOT recommend putting too much down inside the hulls, if you get flipped and have too much weight in your hulls it might be imposiible to right.
Have fun! Sail camping is a blast