I get my carbon fibre reinforcement (1/4" x 1/2" x 18") from Luthier's Mercantile.
http://www.lmii.com/
A stiffer neck seems to promote highs and clarify the articulation of all the notes.
I've installed C/F stiffeners in mandolins, guitars and basses and in all cases they've improved the tone of the instrument. The material adds no mass while greatly increasing the stiffness.
Go for it!
