You don't say specifically where in the area you are.
For general mechanics, I highly recommend Burdette Brothers in Hyattstown (on the Montgomery/Frederick county line). They are a former Pontiac dealer that now sells new trailers and used cars and truck. We've used them for Ford, Dodge and GM products with pretty good results and their hourly rates beat any dealers around.
For 4x4 specific work, consider Adrenaline Off Road in Burtonsville MD. Good folks that tend to specialize in Jeeps (as do many 4x4 shops) but work is generally good.
Contact info for both are on their websites. If you wanted to drop my name (Keith Holman), it wouldn't hurt.