Fedora 7 will be able to install to mdadm RAID10 devices out of the box, but is isn't that hard to add the capability to older versions. The following has been tested on CentOS 5 and should work with RHEL5 and Fedora Core 6 though you'll need new driver disks for the latter.
I do kickstart installs from an NFS server, so that's all the instructions cover.
Download  and unpack in your nfs install directory.
Download Centos 5 i686 RAID10 driver disk and put it somewhere accessible.
Add to your kickstart file:
driverdisk --source=nfs:server:/path/to/centos5-raid10.img --type=ext2 device scsi raid10