Try the icons section ofMac OS X Software from your apple menu...
...or iPod icons from /Applications/Utilities/iPod Software Updater.localized/
iPod Updater 2005-02-22.app/Contents/Resources/Updates/
...or system icons from /System/Library/CoreServices/SystemIcons.bundle/Contents/Resources
http://www.xicons.com/ is the best source for Mac icons as far as I can discern, and I just did a quick search. Search for "iMac" and "iPod" and I think you'll find great icons that are exactly what you are looking for.