Mac Forums

I've recently downloaded and installed the most recent version and it seems to be the one that eats my RAM the most so I realized I didn't need the most recent version (it's one of my obsessions). All I want is a version of iTunes that can play .MP4 music files with as little RAM as possible. I need iTunes because I have an iPod and it's easy to mange music so no alternatives please. :P
I know for a fact that iPod's can work on older versions other than the newest.