I have a Haitian friend who speaks English quite well and has proven himself to be reliable. His name is Lucian and he may be reached at 3417-8384 or 3587-1636.
From the U.S. you would have to dial 011-509-3417-8384 or 011-509-3587-1636.
If you have a car and just need a driver or translator/guide for the day, his daily rate is $20 (U.S.) per day.
If you need a car and a driver, the car costs $20 (U.S.) per day, plus his daily rate, plus you have to pay for any gasoline used.