I currently have this HD & Optical drive setup on my DFI X48 LT T2R:

Jmicron (2 ports):
2 x NEC DVD writers

Intel ICH9 (6 ports):
4 x 250gb WD HD's in Raid 0 (data)
1 x 1tb Seagate 7200.11 (backup of data)
1 x 150gb WD Raptor (OS, apps & games)

I was thinking of getting a pci-e 4x internal 4 port Raid controller card so I can move my 4 x 250gb WD HD's in Raid 0 onto it. I use these HD's for video editing.
Then add in another 150gb WD Raptor onto the Intel ICH9 for Raid 0 with the other 150gb WD Raptor, for the OS, apps and games.

Is that my best option?

I was looking at the Adaptec 1430SA, but I have no idea which brands are good. I also was looking to spend under £100.

What Raid card would you recommend? I need it to be pci-e 4x.