Simple shapes are cut easily with a cutoff wheel and finished with sandpaper... so, you shouldn't have much of challenge Thirdgen...
I am not sure if the options below are cheap, but I am considering them...
2.6mm -
http://www.ebay.com/itm/Carbon-Fiber...item19cc68fdc4
4.4mm -
http://www.ebay.com/itm/Carbon-Fiber...item1c22878760
3.5mm -
http://www.ebay.com/itm/Carbon-Fiber...item1c22878728
Alien