I've had a Netgear Duo NAS for a good few months now & can't fault it
Once it's finished it's start up it's very quiet

+1 for the Netgear Duo NAS, got mine from Amazon along with a couple of 1.5TB Samsung spinpoint drives, should keep me sorted for a while.
Not been using it long enough to give a good review but you can get a free harddrive unitl the 20th Sept..
http://www.netgear.co.uk/promotions.php (Amazon are listed as a authorised seller - only just sent mine off)

Edit: I'd recommend a NAS unit with a mirrored drive system for this much data

I would also recommend a NAS - but cheap they aint.

I've got a Qnap 219p - it hosts my photo website, is used for backing up 3 PCs at home and one from the UK and my local printer is connected to it so I can print from any PC/laptop at home. It hosts my collection of movies, 90Gb of photos and I use it frequently to copy large amounts of data from work so that I can work from home. I would heartily recommend one of them to anyone.

For quietness use a 2.5 USB powered drive. for Cheapness a 3.5 inch.

Have a backup plan based on the drive failing at an unknown point in the future.

What BB are you with? If you have a BT homehub you can plug any USB based storage device into it and use that to access it.