I'm bringing in my work team from around the world (primarily Seattle, London, Singapore, and Sydney) for an offsite in Las Vegas. There are some real business reasons for going there (I work in the travel industry). Anyway, our team activity will be an all-day excursion to the Grand Canyon (presumably the West Rim). I've got a lot of British and Asian women on my team (not that there's anything wrong with that) who aren't exactly the outdoorsy type, but they're super excited about this. So no hardcore hiking or anything...

Anyway, I would like some advice on what the best way (value for money) to get 20-25 people from Vegas to the Grand Canyon for a day. Should we just rent a couple of big vans and drive ourselves? Should we go with one of these limo services (they really seem to by shysters at first blush)? Is there a better way? I'd like to keep control of the trip, and certainly not combine with another group or random tourists.

THANKS in advance!