After having a bit of a fight with CentOS and its broken Realtek 8169 driver (called r8169 and which also claims Realtek 8168 devices but screw up when detecting the link status) I finally got to play with a RocketRAID 1742 controller from HighPoint. Where Promise dropped the ball with supporting hardware RAID on linux (basically you get 2 or 4 extra SATA ports but the RAID controller plays dead), HighPoint promised us true RAID under linux without any wonky software drivers.
Note that the RPM package for the DKMS rr174x driver is attached on the next page.