Heading up and out of Vermillion resort in a couple weeks for a week long trip at 9,000-10,000 feet with my family. Need some advice on clothing, particularly for the kids.

For uper layers, planning:
Wicking tshirts
Mid-weight thermals (Capilene)
Down vests (mom and dad)
Rain jackets
Gloves
fleece hats

Are Mom and Dad going to be warm enough with down vests as opposed to down jackets? Currently, kids haver fleece jackets and I'm having a bad time finding any quality down jackets or vests for them. Suggestions?

I was in that area a few weeks ago, and I had no need for a down jacket. In the evening in camp, I usually wore a long-sleeve synthetic shirt with a lightweight wool sweater over it, and I was fine. I would concentrate more on the sleep arrangements than on what to wear while awake. Also make sure you have some kind of plan in case you get a storm that's more than the typical dinky afternoon Sierra shower.

I'm sure you'll enjoy VVR. It's a very laid-back place where you'll meet a lot of extremely cool people.