These drives will be used in a 4 drive RAID10 array, but not jam packed and not high usage (it's just a single workstation - RAID is for availability). So the environment might be a little heavier than a typical single drive case, but they won't be working hard.
So far I'm looking at the WD
RE2 and Seagate Barracuda
ES.
The WD Raptor looked interesting until I saw the maximum capacity was 150GB

I need 300GB+, preferably 500GB+
Any ideas appreciated!
PS: These are to replace the P.O.S. 300Gb Seagate drives, 4 out of 4 have failed.