I have a Gigabyte GA-EP35-DS3R mobo. I don't need RAID but would like to use SATA AHCI mode (option in BIOS) which would allow actual SATA drivers instead of the IDE emulation (mode). All my hard drives and optical drives are SATA.

I have found via google many old articles and instructions how to slipstream XP and SP2 but I have a newer XP SP2 CD. I just need to 'add' the SATA drivers that I can download from the Gigabyte driver downloads site.

Does anyone know how to do this (i.e. slipstream XP SP2 w/ ICH9R SATA drivers?)?

I read about using nLite and other programs/methods but I would like something simple that doesn't need floppies.

Any ideas?

I would suggest nLite, you won't need floppies. As i recall you need to copy the contents of your xp installation cd to your computer, then slipstream the needed textmode drivers to that installation and finally burn your new xp installation to a cd and you're good to go.