I was thinking of that for the SATA idea, but i think what i might do is get another seritek card. Since out of all the mac cards, it's the only one that's bootable.
There's another one I know: Acard AEC-6890M (RAID, I have one), but it's SATA I only. It has 4 port version, code AEC-6896M (RAID too). There's only one problem with bootable PCI RAID cards: no sleep allowed - KP on wake. At least with these what I've tested.
Well, i had some fun. Found out that running my CPU at 1.58 GHz was unstable as hell. So i dropped it back to a safe 1.42 GHz. For me that is still pretty good. Same speed that my Quicksilver ran at with the Sonnet upgrade.
Also, here is a link that maybe some of you might enjoy...