If you want a WD Scorpio, it must be one with a SATA interface. I got mine at
http://eshop.macsales.com/item/Weste...al/WD1200BEVS/
Works great in my MacBook. Just be sure to....
1. Pay attention and remember which direction the drive sled fits when you take the original out.
2. Be sure to seat the new drive and mounting sled back in all the way.
I'd recommend cloning your original drive to an external drive and then cloning it back into the MacBook after you format the newly installed drive with Disk Utility (on your OS 10.4.6 DVD)
SuperDuper works well. I switched to SuperDuper after some issues with Carbon Copy cloner on my MacBook.