Epitaxial said:
Personally i think the 16Mb cache is worth getting, just for speeds sake and less £'s, Western Digital are fairly reliable drives, after Seagate (i think), check the poll in the Harddrive thread as for how reliably they run, i cant say i've ever heard much difference between the drives i've owned, whichever brand. A lot of noise can be down to how you mount them... eg there are mounts you can buy to dampen vibration on OcUK. (this is just my experience though, i'd suggest perhaps getting more feedback on this)
Out of the two drives you suggested most definately would go for the Seagate... as smids once pointed out to me... the NCQ on those drives can be particularly good.
I mainly suggested the Western Digital as im getting one tomorrow, lol so i am slightly biased