Agree with Allkraut - the 560 is pretty bullet proof and you have more luxury than the other models. He is right on the money about the timing chain....I would also add to check for rust in the soft top housing and in the AC/Heater blower box.
You will have some meaningful shop bills with any older Mercedes - as things just wear out and time is not kind to rubber bushings, grommets and seals.
I would stay away from the 380s for a couple reasons - the single row timing chain and the climate control system.