Wilson owns the division I passer rating record.
Johnson had a slightly better rating playing for a division I-AA team (the university of San Diego, not to be confused with San Diego State). San Diego is such a tiny football program that it does not even offer football scholarships. It's basically a JUCO like the one Portis played for.
I think Josh Johnson is a neat prospect, but he was coached in college by Jim Harbaugh and was picked up by Harbaugh again last year only to last one season- which is saying a lot given SF's QB situation.