This is the only complete commercially available kit that I'm aware of.
Details in this thread on S2ki, with pictures on pg 5 of thread.
http://www.s2ki.com/forums/index.php...=731390&st=100
Kit includes 20 o-ring sealed sphericals (as pictured), installation, and return shipping. You take all 8 arms off and send them to Asura, couldn't be easier.

No affiliation, just glad to see him make something like this available.
Tell him I sent you!