"Are DVD images of Debian available?
Yes - as far as we know, Debian is the only Linux distribution to offer full-size DVD images for download! Because of their size, these images are distributed exclusively with jigdo.
At the moment, only unofficial DVD images for the "unstable" release and official ones for the "testing" release can be downloaded."
Fedora core also offers dvdiso that are bootable.
seems your alpha dvdiso isn't for some reason tho, i've tried and it gives a bootstrap failure
just an fyi