http://www.adventurecorps.com/deathvalley
There is a lot of useful information on his website. DV Double is good support and a great experience. "MetinUz" is right, each year is different and you need to be prepared for Mother Nature. But all Adventure Corp events are very well run and well worth the trip!
And road bike vs tri - whichever one you are able to spend that distance on comfortably.