Finally got the final parts of my computer: the HD's.
Currently, I was using an old HD (a Maxtor 500GB) from my previous system. The idea with the new disks is to set up two Raptors in a RAID0 configuration. As Raptors are already fairly fast, the additional RAID0 - I've been using this method a few years already - should give it an extra edge.
I'm keeping the old HD in to have additional 500 GB of pure storage (like downloads and such, things that don't need the speed).