This sound very good, and i believe DK is also doing the same around these times. I have ordered a 700Mhz AmigaOne G3-XE. I guess i would have to wait until early january, but that doesn't matter.
I would recommend you to go for the XE, cause of CPU-upgradability at a later date. Also be aware that even the graphic cards all work fine under Linux, it doesn't necessarily mean it will do in OS4. My best advice will be to go for the ATI Radeon 8500. This has been supported from the start in OS4, so you will be more than happy enough with this one for quite a long while :-) It still takes some time before ATI 9x00-drivers appears for the AmigaOS, and when it happens, we will also get the new Mesa 5.0/OpenGL 1.4 updated. It may happen in OS4.1 or later version. But for the moment, go for ATI Radeon 8500. Concentrate about the OS4-support, not what is supported in Linux.
Good luck with your machine:-)