I'm a big fan of Amithlon too, but I can't really answer your question so I apologize in advance for going off topic.
I know that my Amithlon machine is using IDE, an Nvidia 5200 and a newer kernel that I found online and it performs reasonably well. The CPU is an AMD XP2400+ I think.
I've been doing a lot of preliminary research on Amithlon lately, but I can't tell you exactly what is supported without a good deal of digging.
I'm looking at more of a replacement/upgrade than I am at what is supported in the shipping version.
As far as I can tell, the only part of Amithlon that doesn't have source code available is the library for exposing x86 to AmigaOS, Amithlon.resource and the PCI library. The UAE tweaks and the kernel are open. Luckily that lib didn't do a huge amount of work that can't be replaced.
Right now I'm looking at pros and cons of which parts should be exposed natively to the 68k side, how much should be handled on the Linux side and what parts of the OS respond well to x86 replacements.
The USB stack would be a good example of mixed 68k/x86. The UI could be kept 68k and compile all the working parts to x86 either as elf files in AmigaOS or built as a resource of the emulator itself.
I'm not sure that having zero chipset emulation is even needed these days. It's not that big of a load on recent CPUs and has huge benefits.
Then again Aros keeps getting better and better, but has none of my old software.
Keep in touch and if I get something usable I'll hook you up if you are interested.
