I agree, stick with the same size all the way around... 195/70/sr(hr)14.
I prefer Michelins over all other brands, but have had good luck with Pirrelli and Yokohama tires. Yokohama are comparable to the Michelin ride and traction in all weather conditions, while Pirrelli perform best in warmer conditions.
Just a suggestion, but when in doubt and price does not factor, by Michelin for best performance and wear.
76 240D (W115) - 550K miles
78 300D (W123) - 200K+ miles