getting rid of the rust

I am working on a 68 barracuda 340 S, I need opinions on rust killers, preventives or removers that I can use before painting things such as rear panels or interior metal interior parts. I have been told Ospho is good, I know that some of you has already been down this road and can tell me some good products. Also can anyone tell me if the panels behind the front buckets are carpeted or vinal, mine are missing and I need to replace them. Thank you all for your help.:???: