Seeing as you are from The Netherlands, there is a good store located there, they also have a webshop and are very cheap on most of their parts.
http://www.alternate.nl
They have a PC-Builder aswell, where you can select the different parts you need and want:
http://www.alternate.nl/html/configu...r/pc/page.html
I work for Alternate.be, it's the belgian store, that's how i know about their prices and all.
so if you have any questions regarding that website or parts, just ask
Seagate HDD are perfectly fine. I have a 2 TB and a 3 TB HDD and they're still good after 2-3 years.
Hitachi and WD are together now as one brand, HGST.