[CentOS] AHCI support in CentOS 5.2?

My friend has an external sata hard disk, and likes the hot-plug feature. 
However, that works only if the appropriate sata setting in the motherboard 
bios is set to AHCI (IDE compatibility and RAID are two other options, but 
hot-plugging doesn't work with them). The machine has WinXP atm, while Linux 
is about to be installed in the following couple of days.

Now, on wikipedia I read that AHCI is supported starting from kernel 2.6.19 
and later, while current CentOS 5.2 has 2.6.18. Is it possible to make AHCI  
work under 2.6.18 or should I install Fedora instead?

Fedora will become obsolete in a year or so, and I will not be around to 
reinstall it again for him, so I would prefer a long-term solution (CentOS). 
But  I need to be sure that it can be made to do all that fancy 
hot-plug-auto-mount-sata-ahci stuff without too much hassle.

Oh, btw, I am talking about hot-plugging using the sata cable --- usb 
connection of course already works, but this is a hard disk and speed 
increase is highly nontrivial when using sata connection compared to usb.

Any suggestions?

Thanks! :-)
Marko