My 630 has a WD 320GB Drive in it. The unit is 5400 RPM (Thus, the 630 does NOT require a 7200RPM Drive as the Original is 5400RPM).
It failed with virtually no usage (while on a UPS so power was conditioned and constant - also in AC Enviroment).
The stock Hard Drive is an AV Drive (though it clearly did NOT help the life or performance of my Hard Drive).
The highest capacity in the WD-AV series is 500GB and can be found for ~$65, but given the failure of the WD-AV 320GB Drive, I am not sure I see any benefit of the AV Series.
From what I can tell, all 2.5" drives with higher capacity than 500GB are Laptop Drives, not specific AV drives (and only a few of the < 500GB drives are specific AV Drives).
I am seriously considering a 500GB Seagate Momentus XT Hybrid Drive, but will probably just put in a 1TB Seagate Constellation 2 Enterprise Class Drive (ST91000640NS).
Both carry a 5 year warranty, so I see little reason to worry about heat from 7200RPM operation (again, as the original 5400RPM drive failed with virtually no use).