Cool looking guitar amps and speakers!Eminence makes a hemp coned speaker. It's expensive, as I assume they probably import the cone. Probably the regulations make it cost prohibitive to manufacture in the USA, but that's an assumption. I never asked; It's not my thing.
I would assume the cone is very durable. I noticed from its response chart that it enters breakup quick and severely, but that's not a bad thing for guitar speakers. It seems like most voice their sound with the speaker's breakup characteristics. It isn't what you would want for FOH speakers though.
Your graphics business is impressive, by the way. In my opinion, aesthetics is a big part of the total experience in nearly everything we do.