Pelican sells the kit.
Porsche Boxster Suspension - Page 5
It comes with everything except struts and mounts. I just replaced all my suspensions 2 months ago. Just order the pelican kit and add struts and mounts. Porsche updated the upper strut mount and the front uses 997 upper strut mount and the rear has 987 mounts.
It is pretty easy to replace suspensions on these cars...