How about the best of both worlds? I have a 1991 300d 2.5, which is the 300E body with a diesel engine. The car has all of the technology upgrades from a 300E and the diesel engine as well? I originally was looking at an 85 300SD or a 91-93 300D. I chose the newer car because the previous owner, owned the MBZ dealership. The car had 167K on it when I bought it, I paid 10K for the car and it came with every single record, including each time it was filled up with fuel.
Good luck!!