Vintage Esterbcook nibs are often quite scratchy. Late 1940's and onwards Schaeffer pens have a much stiffer nib design and may be acceptable for modern carbon copy applications. I can't remember what that newer nib design was called, maybe "Imperial" or something like that.
Also, the hooded nib of a Parker 51 could probably stand up to carbons too.
Platinum also makes fountain pens. The Plaisir is notable because the cap seals incredibility well. The result is that it can go a loooonnnnggg time unused and the ink won't dry out and clog it up. A great pen for those that only occasionally need to use a pen. Fairly cheap, too. Around $20, I think.