No bad choices here
Really, it depends upon what you are looking to achieve. As an investment, only the most limited production AMG items look like appreciating assets to me, the rest were produced in large enough quantities to make them more fun transportation than garage queens. While the sedans of that era never quite got my blood racing, the SL's have always been favorites of mine ever since a family friend loaned me his new SL 350 (R107) in 1972 to drive up to his son for service. I had that car for a week and was (briefly) king of campus at Iowa State!
Is this going to be a year-round driver? If so, the folding hardtop of the post-2000 versions will be a very useful thing to have. In fact, I like the looks of that version best anyway. For a weekend/Summer low mileage driver, any will do. By the way, my experience is that the 350-ish versions, while not as overtly powerful are the better balanced and more fun to drive on twisty roads. This is counter intuitive I know, but I have found this to be the case, on more than one occasion.
As always, go for the one in the best condition and follow your heart! And enjoy the search!