PPC or PowerPC is NOT 68k.
They are manufactured by IBM and Motorola and can be found in Apple Macintosh'es and a bunch of embedded devices.
There are not a lot of PPC motherboards around, and not a lot of OS's for them either, AmigaOne and Pegasos are, in a way, pioneering the PPC motherboard + alternative OS idea (aside from Macs, of course)