Take a look at Rockauto since there's a few choices at a reasonable price. I prefer the Sachs which are factory o.e. . I made the mistake of installing KYB Excel-G shocks and struts but regret it because of rougher ride than the Sachs/Boge o.e. shocks & struts. KYB had a terrific rebate and I was drawn into that dilemma. -Duck

Bilsteins are for high performance cars. I've used low pressure gas shocks on my '81 242 DL and they give a good ride and dampening even with a full load of people and luggage. I've read here that KYB's are not so high quality. Monroe's are good quality and last a long time.

You may want to consider adding air bags to maintain ride height and firmness for heavy loads. You can adjust the air pressure as needed and let air out for no load everyday driving.

A second suggestion is a stronger rear sway bar such as from IPD for stability and safe handling with heavy loads.

All three, shocks, airbags, and sway bar can be done at one time. The air bags go inside the rear springs and require disconnecting the shocks anyway to lower the axle enough to remove the springs which are held in by one bolt at the top and bottom. Be careful not to stress the rear rubber brake lines. By the way, just think, those rubber hoses are over 40 years old!