Short answer:
NO! Not possible at any cost.
Longer:
The latest Mac OS only work on Intel based macs. Support for the G family was dropped nearly 2 years ago.
The same thing apply to the latest applications, they just can't run on any G2, G3, G4 Mac.
You can't replace the G4 processor by an Intel one, they are not compatible.
Electro
May 2013