W126 – but which ones?

I’m currently looking for a new car.I’ve enjoyed the S-Class of the 80s for a long time and I thought that I’d look at it a little bit more closely.So it’s supposed to be a W126 SE or SEL.The engine should be a little smaller, just because of the fuel costs.Which weaker is the one to recommend, the 260, 280 or 300?In addition, the color should be rather dark, i.e. black or black blue or similar. Is it necessary to lie down?