Mmm... the "labelled" trick does seem just *too* easy, right ? Well... You won't install 10.5.x on PearPC, a the emulator doesn't support OSX >10.4.11
Talking about PearPC version as seen on screen is senseless, as PearPC doesn't really have any interface. You must talk about some PearPC launcher... I don't know them all, but the latest emulator core could be found in my sig if you want (be aware : this Redscorp's version isn't compatible with any launcher yet, so you'll have to modify the config file in a text editor).