Which sata-raid do you mean? As you can find in Users Guide:
"...RAID option for the Altos G540 system is provided through either the
onboard SATA controller or through an external controller board
option (LSI 1068 SAS controller or LSI MegaRAID SAS RAID controller)..."
What on-board controller does is "fake-raid". This is not supported on any platform and you do not find esxi-drivers for it. So you can not make esxi custom image with drivers for on-board raid.
Add-on controller is LSI MegaRaid (probably 8708EM2). This is supported by esxi, and you do not need to make custom image (though you might update drivers later).