|You need at least XP sp1 to properly use a 48-bit LBA drive so you should be OK there. You might be in a grey area with a non 48-bit-LBA motherboard and an OS that will see the drive. But it's a good idea to not take any chances.|
For an external drive (not your situation) a person needn't worry about a 48 bit LBA bios since those drives are set up by the OS and not the bios.
As far as installing the card, I've found it best to install the card but leave the drive(s) connected to the motherboard ports. Then boot up and let XP set up the card--you won't need any additional drivers. Once the card is set up, shut down the computer and connect the drives to the card
Oh, and leave your optical (cdrom, etc.) drives connected to the motherboard port. Many of the cards don't work well with those atapi devices.
You're not really green until you're soylent green.