I want to upgrade the hard drive in my 30GB 5.5G iPod. What hard drive sizes are available for this (slim) model? Am I correct in assuming that the slim version (original 30GB) takes 5mm 1.8" drives and the thicker version (original 80GB) takes 8mm 1.8" drives? When I look on the web for 1.8" hard drives, they rarely specify the thickness. And as they I did not see many specs for buffer size and RPM either, I'm worried that a bigger drive may be slower and subsequently slow down the UI? If someone could point me to a website where I can buy a new drive at good price, that would be great. Ideally I would get 80GB, but 60GB or even 40GB would be OK too. And the drive would have a large buffer and would be as fast as possible.