Hypothetically you could make a box that was totally carbon fiber. There are a few logistics problems though. The biggest hurdle is cost, not only is the carbon fiber cloth expensive, it also takes specialty resins to harden properly - again $$$$$.
If you really wanted the CF look, I would suggest that you build your panel/box out of regular fiberglass, then bondo and sand it smooth as a baby's butt. I would try to use Knytex with the proper resin. Knytex has the stregth of regular cloth, but builds up quickly like mat, yet it won't fray quite like mat does. It's excellent stuff, much better than the bondo crap you buy at walmart.
Last, place one layer of CF over the area that will show. Keep in mind that getting the fibers to line up like they do on production pieces is extremely difficult. You could then impregnate the CF with the proper resin, and clear coat the finished product after final sanding.
Here's some sites that may have CF and the resins:
www.selectproducts.com
www.shopmaninc.com