HDD to Stream Multimedia from

I am wanting to allow all computers in my home to be able to browse to a single HDD even if the other computers are not on.

I am currently looking at Lacie and Iomega, but i have no real experience on these brands, nor how much space i would need.

Can you give me a few suggestions of what you guys would use?

So far i have seen these.

http://www.electrouk.co.uk/Iomega-Home-Media-Network-Hard-Drive-Cloud-Edition-1TB?language=en&currency=GBP

and

http://www.macplaza.co.uk/index.php?main_page=product_info&products_id=404&zenid=05d86285e0d6eadc2013ece13ca4f837