Interesting, you have 4 GB ram and Amithlon booted off the CD? I've never been able to get Amithlon to boot on a system with more than 1 GB except for a Virtualbox setup I did with different memory settings (2 GB, 3 GB, 4 GB, 8 GB) and using the mem= statement in the linux boot config for Amithlon (small or amithlon).
Also, if possible, build another Amithlon CD but replace emubox.gz with kernel 3.10 and edit the config files to reference the new kernel in place of emubox.gz. I've had varying degrees of luck with SATA drives. Also check your BIOS settings and see if the SATA controller has a "legacy" mode or "IDE" mode and set it to that. If that lets you see the drive you can start creating the DOS boot partition and Amiga virtual drive.