You must use a ROM flashing utility from one of the third party upgrade manufacturers to get around Apple's deliberate disabling of G4s on B&Ws. I forget whose utility - check xlr8yourmac.com's FAQ or model specific pages.Yes, I think you can.
If you attempt to boot a B&W with a G4 ZIF without first flashing the ROM, (IIRC) you end up with a large brick.