Well, it took a lot of reading and a lot of trial and error, but I got a great toolkit, unlocked, rooted and after three tries, I finally got Jelly Bean up and running.
Thanks for all the suggestions. Even though I didn't use them directly, they led me down the right path to success.
So far, so good with JB!
Here is the toolkit I ended up using, FYI: http://forum.xda-developers.com/showthread.php?t=1392310