The surface of the WD1200 heats up to 45 degrees Celsius, but that is no reason to worry. Temperatures below 50 degrees Celsius won't cause trouble - all it will do is heat up the computer case. Nevertheless, there are hard drive cooling solutions available which ensure that the drive won't ever fail due to overheating. Check those solutions out if you want to be sure about this issue.
Drive Idling Noise
There is hardly any difference between the WD1000, WD1000 8 MB and the WD1200. All of them maintain acceptable noise levels without being really gentle on the ears.