to give a little help to the other OSX PPC user around I have put the recent SDLMame binaries in this Mediafire place: SDLMame OSX PPC
Please note that I can't offer ANY support about it, I made those binaries for myself and they works nicely on my G4 MDD machine, please don't bother the SDLMame team about any issues you should have with them.
Based on my experiments, for an optimal MAME experience (limited to classic games, of course) it strongly recommended for the G4 family the PPC7455 based (with L3 cache) over the PPC7447 with no L3 cache. Of course a G5 is even better.
Keep in mind that above binaries are command-line only, if you don't want to mess up with typing strings on Terminal you need a GUI frontend like the EXCELLENT MacMameInfoX that runs very well on PPC OSX too.
As final reminder, be sure to have the appropriate SDL.framework installed in Library/Frameworks or nothing of above will work :-)
Many of your questions can be answered if looking at various thread around here so take your time to do a little search
Have fun! :-)