if im reading your question right youwant a safe way to download youtube videos to .mp4 for your itunes this site works really good
Will you get virus when you uses all this converting website to change youtube video to put in your itunes!?
You brother is wrong, as of today, no viruses can be spread using video or audio encoding which is exactly what you are downloading from the websites. Some websites will even give you a free converter so you don't even have to go to their homepage and can do it on your own computer.