Well, if it's for SP's you can sort on Yahoo by average K's per game. It's not K/9, but it's jsut as good for H2H leagues. For Roto leagues it's not as accurate if you have an IP limit, but still helpful.
I know a few sites that have K/9 from past seasons, but none that have it for this season.
"Jack, will you call me, if you're able?"
"I've got your phone number written, in the back of my Bible."