Cheers! For the frame kits...I'm building a list of people who want them before getting the next batch made. Need a few more names and I'll get them going. (take 1-2 weeks to get a run machined, assembled and sent out)...I wish I could keep stock...but am not in the best place to do that right now.
As for rigidity... I believe they are over engineered for what is required of them, and have no worries about running the bike with a Gordon kit installed, as they are quite beefy. Although many people will argue that any cutting of the frame will skew it's original rigidity...you can read thru the discussions and forum members comments. I haven't heard one complaint from somebody who has installed the kit yet....and I don't think Gordon has either...since he started making these years back.
Let me know if you're interested and I'll put your name on the list...hopefully get some going soon.
Cheers,
Brendan