There are a few options. The Schneider 240mm lenses cover 180mm x 240mm, however, they have (8x10") in parentheses after that. Obviously that is not a direct metric conversion, so they presume you are not printing full frame. From what I read, are very popular and seem to work well. Also there are process lens options out there in the 250mm focal length. Going from 300mm to 240mm gets you about one paper size bigger.
Originally Posted by 2F/2F
With the grain magnifier at the corners my 300mm is sharper than my 240 Componon-s when wide open, but I don't print wide open so I suspect the prints would be nearly identical. So I don't see any need to repeat the comparison that I suspect many others have done. My head goes almost all the way to the top, so I have not had a need to use the 240mm yet, though I have had it for 6 months or so.