You should get the complete wiring harness from the '04 bike also plus the ancillary parts like the rectifier; you'll also need headers (with O2 sensor) from later bike. Cooling system is different - will need to modify that also (thermostat & temp sensor in the motor on later bike)
Do you have MC1000 or MC2000 ECM? If former, you will at least need the tune from later model.
Yes it can be done - there's a lot to it.

__________________
GSXR 1000 Front End Swap