What you do, is download the SATA drivers from the motherboard's website, and put them on a bootable floppy disk. When you press F6 during the install, it'll check the floppy disk and load the drivers.
Another option, is to create a slipstreamed disk. You can use a program such as nlite, and you can download SP2 or SP3, and slipstream it into a new install disc. The newer SP's have the SATA support in them.