I forgot to publish the news, that since saturday there is a new machine on my network. My first AMD64, see dmesg for details. It is also the first machine with a Gigabit NIC.
Installing FreeBSD-amd64 did work without major problems, after I figured out, that I need to force the NIC to use 100Mbit, because Autonegotion with my El-cheapo 100Mbit Switch did not work. Also the ATAPI CDROM is not recognized after the boot although I booted from it during Installation.
Ports mostly work, next weekend I will probably have installed everything to make it my workstation. Only Problems so far: No Java, because the linux JDK is i386 only and no video, since mplayer configure check failed and xine failed because of the usual PIC problems in djbfft, which should be fixable.