I use and recomend this mob here http://www.fulcrumsuspensions.com.au/superpro.html
They do not turn to powder or crumble like other brands that I have used.
They come with thier own special grease too, it's white and very tacky.
I also have them in my Falcon, front to back, have been in a previous Falcon before this one, so they are about 8 years old now, and still good.