First thing would be to update the BIOS so that the controller into IDE / SATA. The driver with ESXi doesn't seem to support RAID at all with the ICH family.

Then, one of 2 options
1) Put ESXi on a usb flash drive, boot with it and then modify oem.tgz to include updated files for pci.ids and simple.map. Then reboot and check that it 1) recognized the controller / 2) properly loaded the driver for it. With the USB flash drive you could also just access NFS or iSCSI

2) If you want to install directly to the hard drive from CD you could try this. I haven't verified that this will work - I'll try it tonight or tommorw.
a) On the install CD modify oem.tgz and rebuild the CD with the new copy. I've been doing PXE installs myself rather than doing this.
b) Assuming the change is correct and the driver will work with the ICH9R, the install process with then extract the install image from install.tgz and write that to the drive.
The problem will be that the image also includes a copy oem.tgz that would need to be modified. The file is buried in a dd image so I'm thinking the below would be better.
c) Once the image is install, reboot the PC and boot with a Linux live CD. I tried slax 6.0.7 last night and it mounted the hypervisor partitions.
d) Update oem.tgz on the hypervisor1 partition and then reboot to ESXi

Like I mentioned, this should work, but I have not tested method 2. Method 1 was done here - http://communities.vmware.com/click.jspa?searchID=-1&objectType=2&objectID=1006408 and the thread will detail how to deal with the oem.tgz file.

If you run lspci -p, does the module show up for that device. In the below example on a whitebox of mine I added the changes to pci.ids and simple.map for an Intel 82556DC card, and ESXi then sees it correctly, but the module doesn't get loaded properly for it.

/mod # lspci -p
Bus:Sl.F Vend:Dvid Subv:Subd ISA/irq/Vec P M Module Name
Spawned bus
00:00.00 8086:29c0 8086:5044 V
00:01.00 8086:29c1 0000:0000 255/ /0x81 A V
00:03.00 8086:29c4 8086:5044 11/ 11/0x81 A V
00:25.00 8086:294c 8086:0001 9/ 9/0x89 A V vmnic1
00:26.00 8086:2937 8086:5044 10/ 10/0x91 A V usb-uhci
00:26.01 8086:2938 8086:5044 11/ 11/0x99 B V usb-uhci
00:26.02 8086:2939 8086:5044 9/ 9/0xa1 C V usb-uhci
00:26.07 8086:293c 8086:5044 9/ 9/0xa1 C V ehci-hcd
00:27.00 8086:293e 8086:3001 10/ 10/0xa9 A V
00:28.00 8086:2940 0000:0000 255/ /0xa1 A V
00:28.01 8086:2942 0000:0000 255/ /0x89 B V
00:28.02 8086:2944 0000:0000 255/ /0x91 C V
00:28.03 8086:2946 0000:0000 255/ /0xb1 D V
00:28.04 8086:2948 0000:0000 255/ /0xa1 A V
00:29.00 8086:2934 8086:5044 11/ 11/0xb9 A V usb-uhci
00:29.01 8086:2935 8086:5044 11/ 11/0xb1 B V usb-uhci
00:29.02 8086:2936 8086:5044 10/ 10/0x91 C V usb-uhci
00:29.07 8086:293a 8086:5044 11/ 11/0xb9 A V ehci-hcd
00:30.00 8086:244e 0000:0000 007 V
00:31.00 8086:2916 8086:5044 V
00:31.02 8086:2920 8086:5044 11/ 11/0x99 A V ata_piix vmhba0
00:31.03 8086:2930 8086:5044 10/ / B V
00:31.05 8086:2926 8086:5044 11/ 11/0x99 A V ata_piix vmhba1
01:00.00 10de:01d3 1682:227e 11/ / A V
03:00.00 11ab:6101 11ab:6101 9/ 9/0xa1 A V
05:00.00 8086:107d 8086:1084 11/ 11/0xb1 A V e1000 vmnic0
07:03.00 104c:8023 8086:5044 11/ 11/0xb1 A V
/mod #