Good news: mol supports panther.
Bad news: airport extreme is not supported, broadcom refuses to release info on their chipset=no linux driver, there are some efforts underway to reverse engineer or make a wrapper for the driver but these may be a ways off.
I run Gentoo on my PB G4, and just use a cheapie wireless card for now. Everything is really well supported with the PPC gentoo distribution. I suggest you check t out.