Prettyboy, prettyboy, and yet MORE prettyboy
There's actually quite a lot of media for Nash and the Suikoden games in general. As many characters appear in more than one installment of the series, and with spin offs like Card Stories floating around to boot, any major character probably has quite a bit of art about them. Here are some images of Nash, roughly arranged in chronological order.
That Alex girl sure is awesome
My friend/affiliate/Suikoden partner-in-crime Alex scanned some of her Suikoden III artbook for this site :) Thanks Alex!