I finally got my PCI Express SATA II cards working with Debian GNU/Linux!
PCI Express and SATA II are relatively new technology, so support hasn't been fully established by the open source community. Still, these look to be solid technologies that will be around for awhile, so I've decided to get started with them now.
I had incorrectly upgraded them with the 7045.bin file, which caused the system to freeze upon the Sil 3132 bios post. I re-flashed the cards with the r7045.bin file and now it posts fine and continues booting. :-)
These are really great cards for the price. With a few minutes during the debian install you can build a really sweet raid5 system. Very nice indeed.
FYI: I think these cards use either the sata_sil24 or siimage kernel modules, which are commonly available on linux.