Question: I just updated my fascinate to CM10 Nightly built rom. Currently I'm running EH03 radio. I googled everywhere and I can't seem to find one right now. Now...where is my radio update?
Answer: With radios, it is always a good idea to follow the rule 'if it ain't broke, don't fix it'. Flashing the radio is one of the few ways you can completely brick your device. If you aren't having any problems, I would just stick with your current radio.
Question: OK. Where is my kernel update then?
Answer: That goes same for kernels. Most of the time, kernels are rolled with custom roms as package...and therefore you don't need to risk yourself by flashing the wrong one. If you really have to, then you can google it yourself.