Why not compile on the Z? At least two reasons: the z has a slow processor, compared to most desktops; it doesn't have much RAM. I was having wierd compiler errors on the Z which were due to running out of memory. This did not happen in the cross environment. Unfortunately, I discovered other reasons my favorite emulators, dosbox and generator, won't compile--basically they do some low level stuff and need someone who actually knows something about C/asm to port them.
You can set up the x86 cross environment on your PPC mac if you have virtual PC and a fast >550Mhz Mac with lots of RAM. I have a daystar-upgraded pismo 550 G4 w/512MB and I have been building stuff in a virtual (gentoo) Linux machine. The cross compiler runs about 2X as fast as the native zaurus one, which is really not a big improvement, but I wanted to see if it could be done
. You do not want to try this on a Wallstreet.