CDRWs just fit fine that purpose, btw ...
Snatcher seems to hang in KEGA 0.04b if read ahead option is enabled and you are using a real CD-Rom disc. (Maybe it's a issue related to my specific configuration, but it's a worth mention anyway)
Kega won't run isos from emulated CD-Rom due to the way it fetch the audio data. It relies on digital data extraction. I consider it a really good feature, but the problem is that at least the emulated CD-Rom I tried (daemon tools) won't liked the way Kega tried to acess the data.