I, also, have been looking into these wheels... The most informative site I have found is on the following website (need to copy and paste the link, the "Insert/ Edit Link" edit tool did not allow me to post the entire length of the link):
www.oclbrorssons.se/6249_SE.67EA239344e193626da5d17d43ce4a94b16ff6a0?webbid=5&webdid=416&webban=1
On the right hand side of the page, clink on:
"TEKNISK INFORMATION" for details on various sizes, offset, weight, etc.
"BILDER" for quite a few photos of the wheel.

RC, could you share with us more on why less unsprung weight is not always a good thing?  The review of the 997.2 TT on Excellence also stated something similar (I suppose): "The Turbo center-lock wheels weigh more than thee GT3 rims because the Turbo is heavier than the GT3" (December 2009 issue, page 79). 

Not trying to set any flames here... just trying to understand the topic more before I dive into my next mod, potentially the BBS Fi...