probably the best place for them...
so long as you make it very clear that they are not to be handled unless absolutely necessary. We all know how we all want to reach out and handle them - and that goes for the vet office staff, too. Is your vet an exotic animal vet and understands the needs of chams (I assume so since s/he is your vet
It should be stressed that yours will be in a new environment, smells, sounds, sights, etc. Do you know where they will be kept? Will temps be modified? Will they be using your caging or some setup at the vet's? I would also insist that only one person be the "keeper" for feeding, etc. and meet with that person beforehand.
I board my cats when I go away and even though I have been using the same place for years I have a typed up sheet of info. So you may want to give them something for reference. The only other consideration I can think of is that they are isolated so they will not be exposed to anything they can "catch." So I guess the bottom line is a clear understanding with your vet.
I know if it was me I'd be calling every couple days to check in - actually I do that with my cats! So I understand your hesitancy, but unless you have someone you can count on to come in every few days to feed, clean and water I think the vet office is great. There have been discussions on other forums (probably here, too) about micro-managing and how some breeders/keepers leave their chams for several days at a time with minimal care and all are fine. I think having one or a few as pets compared to breeders who have many, thus their interaction with them is a bit different.
Enjoy your time away and don't obsess too much or folks will start calling you "lele" :E
lele