Thanks for the reply, I think you are right this machine has way to little memory and I can't get at the (SCSI) disk to get some swapspace either for some reason.
I left the machine on overnight and it got all the way to the AV-setup wizzard (but does not seem to get past the resolution/refreshrate selection). So I guess that answers my original question.
I tried removing all it's devices except for the ones I want/need, but I cannot seem to get rid of the mythtv-backend, it keeps getting started anyway. All I really wanted from it is to be able to use it's (SCSI) cdrom drive, it was a nice experiment anyway. And I might make a wiki page on how to pxe-boot machines with grub instead of the usual nic-bios.