The drivers are located at ASRock > N68C-GS FX For the hard disk controller you want SATA RAID Driver on that page. It's a zip file and when you extract it, you'll want the folder XP_RAID. You will need to slipstream them with
nLite (requires .NET 2.0) unless it has a floppy drive which I very much doubt.
When you slipstream, you want to do it as text mode drivers as shown in image #11 at
http://xdot.tk/nliteimages.html. That dialog will pop up automatically when you select nvrd32.inf from the XP_RAID folder.
Let me make some suggestions since you are already going to be using nLite...
Have nLite slipstream SP3 if your disk is not already SP3.
Go to http://xdot.tk/updates.html (my site) and download, unzip and run the bat file from UDC-mm-dd-yy.zip. This will download, from MS's servers of course, all the high-priority updates that have been released so far.
Add them all to the Hotfix, Add-ons and Update Packs section of nLite.
Slipstream the rest of drivers with nLite.
First download the rest of the drivers on the ASRock page and extract them so that you have a folder with the drivers and .inf files only. You don't need the setups and all the other junk. You may need
Universal Extractor to extract them or a lot of times when you run the setup on another machine it will extract the contents to a temporary folder, usually on the C drive. If you don't close setup. You can
grab the folder that contains them before setup deletes them.
When you've collected all the drivers .inf and driver files, it's simply a matter of adding them to the drivers section of nLite. To do that select drivers in addition to the one for the SP and the one for the updates in the task selection screen, Image #4
in the previously mentioned page.
You can also make the CD unattended, do some tweaks, and other things. Just select them in tasks.
Whatever you decide to do, make sure to do bootable ISO and when you're at that section click Make ISO, not next! Image #39.
Here's a somewhat outdated guide on using nLite: http://www.nliteos.com/guide/