I dunno for sure if they bolt into a 6th gen Civic, but they went into my 5th gen just fine...only had to swap the rails over. It's not hard, but enough of pain that you wouldn't want to be putting them in and taking them out everytime you raced. Besides, they're perfectly comfortable for daily driving. Someone else will have to tell you for sure if they'll go into a 6th gen...

Other than that, they shouldn't be terribly hard to find, but don't pay more than $200-250 for a set in pretty darned good shape. I paid ~$180 for mine, but have seen a junkyard selling them for $300 *apiece.*