Im happy where ever it is, couldn't make indy 2 years in a row, but will be at texas next year! I do have a suggestion though I love the phoenix idea.... LOL
Rocky Mountain Raceway -
http://www.rmrracing.com/
Drag strip, autocross area (east of the oval track), vendor area (why not just set them up in the oval on the grass and leave the track/tarmac for foot traffic), and car show on the other side of the drag strip...
Add in that its probably not that expensive...
Not sure on hotel/accommodations though didn't look around that much.. but im sure SLC has something...
Add in that its pretty "central" to the west coast!