How to take a group rappelling near Moab without offending absolutely everybody:

I've just been voluntold to help find, coordinate, and execute a 'rappelling adventure' (their words, not mine) for a large group of about 15 people.  My normal MO is to only take whoever can fit in my Corolla and leading or sport climbing on our own, so this is a stretch for me.  Any suggestion on how to pull this off without it becoming an absolute mess would be appreciated.  We'll be camping South East of Moab - towards Mount Waas, so bonus points if you have a location you'd recommend.  

Are you getting paid or otherwise compensated? If so, the BLM will need their cut. What's the scrambling ability of the group? What's your ability to set up anchors using distant components like rocks and trees?

Advice: fake your death; find one or two good partners; climb neat stuff.

Rappelling is the most dangerous aspect of climbing.  Just do when necessary.  Go climbing.