That's Terry Clanton's car, which was for sale at one time. I think he has since decided to keep it. You can see the thread here:
TClanton's 300SD
I would venture to say that a W116 in the price range you specified would be in too bad a shape to be practical. W123 with a turbo would be better. BTW, to avoid confusion, the T in 300TD specifies a wagon body, not a turbo. To say turbo, you have to say 300D Turbo.
Best of luck with your search. This is the fun part.