After trying to be smart about it and figure out my own way to get Ubuntu 8.04 on the RAQ3 I decided to just suck it up and follow others leads. So, I followed Jim Tuttle's site about getting Ubuntu 6.06 on his Qube. The Qube and Raq are very similar as far as I can tell so I thought I would have some success with this. I combined this with Tim Wiley's instructions for building a fresher kernel. Success! At this point I had a working Ubuntu 6.06 install.
So, I crossed my fingers and used upgrade-manager to bring it to 8.04. The first time I ran it it timed out on one of the mirrors. That was a little scary but it looked like it probably recovered ok from it so I tried the same thing again. Success! Almost seemed too easy. After some time it asked if I wanted to remove obsolete apps so I did and then asked to reboot, which I did. Came right back up and showed 8.04 and the uname -r still showed my custom kernel.
Sweet!
I haven't really put any time on the box yet so I don't know how it'll perform but it looks pretty stable right now. I'm going to try to clone the drive to the RAQ3i drive so I don't have to go through the rather lengthy process again. It all works but it's hours long. Kernel compiling on the RAQ isn't what I'd call a snappy process.
More later once I get Asterisk up and running.