Hi Tekdes,
As mentioning in a thread I posted earlier today (
http://forums.dlink.com/index.php?topic=37454.0 ), I'm using the following disk:
Hitachi 2TB 3.5" DESKSTAR 5K300 SATA 6GB/s Coolspin Hard Drive - 32MB Cache - HDS5C3020ALA6
Also - take note of
ftp://ftp.dlink.co.uk/dns/DNS-320/compat_list/DNS-320_CompatibilityList.pdf - which is the most upto date compatibility list.
The disks you've mentioned though:
HD204UI/Z4 - I believe doesnt have direct warranty with samsung, only the reseller - something to be aware of (whether its a grey import i cant say)
I cant say much about the ST2000DL003 - it looks like it may have 4kb sectors which may prove a problem until dlink update the firmware for the dns-320...
I'd also stay away from 7200 drives - too much heat for a small enclosure. The speed benefit of the drive wont be noticed as the max interface speed is 1gbit..