Try Bob Ennis. Great service and he is very flexible.
http://www.mtwhitneyshuttle.com/The Mt. Whitney Shuttle Service
Shuttle Service for the Eastern Sierra
P.O. Drawer A, Lone Pine, CA 93545
Telephone: 760-876-1915 Best time to call: evenings (Pacific)
e-Mail: info@mountwhitneyshuttle.com
Transportation to and from trailheads in the Eastern Sierras