What do you want to do ??? For more detailed places ask the same question on the blue mountain jeep web site. http://www.bmja.org
I don't go down south too often for 4x4 shops but the two main ones around here are:
OK 4 wheel drive in Stewartsville NJ, 1 1/2 hours north east of philly. 8 indoor bays, clean, good work. I *think* everyone who works there owns a jeep
Pocono 4 wheel drive, RT 611 near bartonsville pa, about 1 1/4 hours north of philly.