I too have been trying to implement the High-Point raid controller on SME 5.12. I have been able to successfully compile the device drivers for linux 2.2.19-7.0.8 (whew...), and I believe I have successfully created a driver disk in the correct format for RedHat (required uncompressing modules.cgz, adding new directories & driver ELF file, then recompressing).
I am able to install directly to my raid0+1 array - ALMOST... (see update below)
To save others considerable effort, I have posted a zip file containing the entire contents of a HPT374 driver disk for RedHat (including the e-smith 2.2.19-7.0.8 kernel version.)
You may download it from my website at
www.jeffandsteph.com/highpoint/hpt374.zip. Just unzip the files to a blank ms-dos formatted floppy.
I'm honestly not sure how to correctly use a driver disk with the e-smith kickstart process (as there are no opportunities to select additional drivers), but I can tell you how I loaded the driver during the install.
1) have your raid array installed and configured using the Highpoint bios utility.
2) start the SME 5.12 install process from cd-rom.
3) type accept at the first prompt (to load the boot image)
4) when you get to the license agreement, switch to console 2 [Alt-F2]
5) insert the highpoint floppy and mount: # mount -t vfat /dev/fd0 /mnt/floppy
6) load the driver: # insmod /mnt/floppy/hpt374.o
7) Switch back to console 1 [Alt-F1], accept the license and continue the install.
UPDATE: Here's where I'm still "expanding" my knowledge of linux boot process. (any help would be appreciated

SME successfully installed directly onto the raid array, but the kernel boot image still doesn't know how to deal with raid controller. I.e. the kernel starts, detects the processor, drives & other hardware, but panics because it can not mount root (because it doesn't know about the new device driver yet.) - the proverbial chicken & the egg problem. I suspect I can modify the modules file reference by the boot image, but I'm still working on a way to successfully do that. Will keep everyone informed.
I look forward to our mutual success.
At your service,
Jeff