I had the same feeling when I was doing my suspension refresh, that there are just so many options. For that reason, I opted for the simple route of mostly OEM parts with a few upgraded items. The Z4M parts I referenced refers to parts that fit the BMW Z4M.

Now, I'm by no means a suspension expert (far from it). You can see what I replaced at 50k miles just a year or two ago in my car in my 50k suspension refresh thread (LINK: http://www.zhpmafia.com/forums/showt...miles-10-years). I replaced those parts due to either being worn or just old. I did not change the sway bar bushings since I plan at some point to change the sway bars themselves (either E46 M3 front and E46 330Cic rear or something like UUC/TMS/Hotchkis).

Someone with far more suspension knowledge will be by to lend a hand, I'm sure.