http://www.courtesyparts.com is where I got my brake hardware kits, 54 dollars shipped for front and rear: sliding clips, shims, and grease. Its a bit much for a few thin pieces of metal, but works perfectly. my old brakes had no shims on them, and they squeeked a bit under braking, and they were nissan oem organic pads!
also i recommend buying some disc brake quiet spray at your local napa/pepboys/autozone. you just put the pads face down on a news paper and spray a few coats onto the back of the steel part of the pad. it does its job well. do not do this if you dont get shims though, because if it comes into contact with any sliding parts it will gum the part up (aka the piston).