I am currently riding a 07 yz 250 and have been planning on purchasing an 08 450xc in addition.  My riding buddy rides an 07 300xc, which I really like, I just intended on buying a four stroke.  If I read your info correctly, currently you are only working on frames for the 450xc-f.  I am extremely interested and capable of purchasing a bike set up with your AWD system.  thanks...