The replacement is not difficult at all. Take a read of my DIY on it...
http://w124-zone.com/?p=65
Very straight forward.
My struts were toast at 82k miles...You will notice a huge difference just by changing the struts and sway bar bushings. Unless you have wear on the tires, I would definitely do the sway bar bushings (front and rear...especially at 211k). It will no joke feel like a completely new car.
I've had great experience with Bilstein. I've used Comfort (do not recommend due to possible raising of the car...very comfortable though!!) and sport.