You probably want to use around a 6 ounce cloth. Do yourself a favor and buy common weave rather than twill. The twill comes unraveled very easy, especially when handling with gloves that have some epoxy on them. The twill works good if you are doing compound curves as it will lay down better, but for me anyway, it is harder to work with. Freakin' strings of that stuff everywhere. Not sure that carbon fiber is worth the extra expense over fiberglass cloth unless you are vacuum bagging and curing it.