i wouldnt even try, you are talking about a super slow and weak processor and 256 megs of ram, if you could install it (which i doubt) it would run absolutely horribly.
I installed 10.4.11 server long long ago when the patches first came out for fun. But after AppleTV was updated I went back to using it as an AppleTV. I revisited the installation today. Yes it's slow, but lightning compared to a 10.4.6 installation on my PowerBook G3. ;)
Safari, services, ethernet, sound all usable, but using the semthex 8.8.1 kernel with the improper FSB settings is a real pain.
I tried everywhere looking for the magical 8.9.1 kernel, but it seems like vaporware. I wonder if anyone out there has it.
I will try the Leopard approach as there seems to have more active development. Actually Leopard was my main goal a few years back as to have the cheapest Apple-Branded iPhone development platform available. I guess the hackintosh scene has finally caught up.