I'm with Michael, I too would prefer the SL with the LH injection in 500 form. The twin cam V8's are definitely more powerful than those in the three valve design. Also would stray towards the 320's with the HFM injection and not the hybrid 104 w/103 injection found in the early SLs and coupes. You'll feel the difference. And DONT feel deprived at all with the 104, they still MOVE considering the weight surrounding it. Although I believe that the 5spds were only offered with the 300SL's, 90-93?. TOUGH CHOICE! Eventhough the models are virtually identical, it's what is connected to your right foot that gives you that peace of mind. Good Luck.
Bill