Shawn,
The only carbon I've been been able to get my hands on is the Gordon's unidirectional that Bingham carries. I was a little unsure if I could use it directly on the back if it was sanded both sides. I've also read in other threads that is dinged up easily. I would like to find the cross weave carbon that is sanded on one side and clear on the other side. Not sure what they call it but I've seen guys leave it that way or skin it.
As far as the core tuff it's pretty much an accent, I think it may add a little stability, probably more so on a curve. I am getting pretty good numbers with the Bo tuff in my normal bows. Usually 178 to 185 @ 10 gpp drawn to 28.
This will be my first time messing with the foam and if it's 30% less stack I need to get ride of something .
Cory