Well... with a Friday afternoon to spare, I have taken the plunge and decided to nut out all the implications for installing Linux on a SunFire T2000.
Google searching doesn't yield a lot of useful instructions - the most interesting comment I found was that people had google'd for installing Linux on a SunFire T2000 and found no links! Here's hoping this article will be useful to someone else.
Ok... first things first...
The single biggest issue with getting this to happen turned out ...