X3300 (got it right this time),
I think the 100mm extension idea stems from the folks @ HPN.
I'm currently working with Phil @ Aftershocks (Palo Alto) on the proper shock for my rig (Wilbers custom). He may be able to add some insight to your project as well... smart guy, when it comes to suspension/geometry.
Really enjoying your thread.
Thanks for taking the time to post.
Industrial Tiki Purveyor