Get a 500Gb SATA drive if you have a PC. If not, still get a 500Gb drive. You can store 750 or so full CD's on it with no compression. Later get a second one and run them mirrored for data backup. My music server has two mirrored 1Tb SATA drives. I can store around 1800 full CD's on one. If you are not wedded to iTunes give Foobar a try. Also, if you are using a music server get ASIO for all. It bypasses the windows Kernal mixer and gives much better sound. I would suggest Songbird (which I really like) but it doesn't support ASIO.