A leak that appears to be in that area can be misleading. When I first got my Jeep, I had a head gasket leak that went down the back of the motor and between the trans/engine. Could be pretty simple.
Also, with the rear main seal, I have heard that it is kinda easy to install the new seal backward and that will cause a leak. If you have basic tools and somewhat handy, I say give it a shot yourself. Took me a couple of hours and a couple of beers.