I bought them on ebay from here :
https://www.ebay.com/usr/completestruts
As for my e53? No. But that is because I want to run koni struts since I can adjust them to the ride I like. I have the koni's on other bmw's I own and love them for the adjustable part.
If I didn't want the adjustability part I would try them at least once. They are so cheap it would be nice having a spare set of springs if nothing else. Also if you are not experienced working on cars and don't have a set of spring compressors and are wanting to do the job yourself then I would definitely go with them. All together like that will make the install a breeze.