Just one comment, I'm not a big fan of single pivot suspension designs. They do have their merits, like durability and simplicity, but I don't really like the pedal induced bobbing inherant in all single pivot bikes! Besides that, it appears like a nice set-up.
BTW, if you're racing XC, why do you want 6" of travel? Or was that just your friends bike?
L8R
__________________
"Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming, "WOW, What a Ride!" - unknown
"Your Bike Sucks" - Sky Yaeger