So i put it in the /var/lib/tftpboot/sardu folder and changed all cfg files to have the new start sardu/. It worked perfectly with my extra Acronis True Image Home 11 (not 2011, because i didn't bought it.).
Problems are with the Windows Live CDs. They won't boot. The Linux Live CDs are a bit better. I tried Ubuntu Live CD and it started but run into busybox.
I know i can boot iso now with memdisk but it's better not to boot the iso alone over the network if you have a 4,7GB DVD and your PC has only 2 GB RAM

I'm going to test the rest and to tell you my solution if i can find one

My the force be with us
BlackHell