The 68k UAE works OK under amithilon, but you realy only need it for games. Most other apps can be retargeted with "Newmode" if they needit. I had amithilon running on a Athlon XP 1800+ it was like having a 2GHz 040, But I nolonger use it as the Hardware I wanted was not compatable, almost no ATI support and forget many of the SATA controlers, limit of 1GB mem max, seems to me that the best hardware was in the Athlon XP range. it just wont boot on my dual Opteron setup.
But On the correct hardware you wont look back.