guys, the Ozonic has also 4 AD/DA and mic-line preamps http://www.m-audio.com/products/en_us/Ozonic-main.html
the preamp-converters I suggested can connect through the Toslink straight to your G5.
you can keep the keyboard of course for controller and notes..
generally I try to stay away from "do everything" machines.
and get stuff that can do one thing very good. a stable of one trick ponies.