I don't know how helpful this will be, but in case anyone else is having a similar problem, I felt it right to share my experience.
I pre-ordered OS X a month before it was released, and tried to install it on the last Beige Macintosh they ever made - a G3 333 UWSCSI minitower.
The install CD did nothing but kernel panics, even when the machine was stripped to bare bones stock. It's now about three and a half months later, and after trying almost daily, OS X is finally installed.
Read the rest of the article if you'd like to see how Glen finally got OS X on his beige G3...
Here is what I did. As I said, I stripped it to stock configuration. Only, this time, I thought I might pull and plug stuff while the process was ongoing, so I left the case open and plugged the power cord into the now upside-down power supply.
I was, of course, concerned that the Install CD might not be happy being read upside down, but I felt that after 3+ months of trying, I would go for it. The other thing I tried, was to move the CD ribbon cable to the other IDE plug on the motherboard.
Now, I don't know if it was plugging the CD into the other IDE plug which finally did it (the likely story) or the fact that the computer was upside-down (the unlikely story) that finally did it, but it suddenly worked.
So I went through it all, completed the upgrade to 10.0.3, and then put everything back together - now it's working like a champ!
So, when all else fails, try turning your computer upside-down, you may be surprised. ;-)
Shalom!
Glen
Mac OS X Hints
http://hints.macworld.com/article.php?story=20010525000352350