I had this same problem with my 00 Limited. Most of my HVAC control lights went out (the digital control kind) and I was able to replace all of the bulbs with little headache.
However, my factory radio and CD had been dark for a long time. After much, much searching on the subject, I found out from a good friend of mine who is a service writer for Toyota that the lighting behind the radios and CD players is "non-servicable"!!
I just went ahead and went with an aftermarket stereo (and VERY glad I did). This is pretty much your only alternative unless you can find someone on ebay selling a factory unit. You have to make sure that the plugs on the back are the same if you get a factory unit somewhere... they were different on certain models and such.
Hope this at least shortens your search for an answer.