Hi Max. I usually convert all my comics to 700 x 1022, and they all have looked good to me, and not blurry. I use Paint Shop Pro, a very good program for images.
But for my future uploads to this site, I certainly can make them larger, perhaps 750 x 1040.
Well, I don't know if many guys ever get interested in romance for comics, but today I've bought some from good ol' ebay, and also plan to bid on more the following days.
I'll try to scan them soonly for y' all.