The closest you will find is the original AMT '64 Grand Prix.
There was never a '63 produced, although there may be a resin one out there somewhere.
The problem with modifying a Bonneville is the wheel base.
The Grand Prix was built on the shorter Catalina chassis.
120 inches as compared to the 124 inch Bonneville.
4 inches doesn't sound like a lot, but it makes a huge difference in appearance.
Steve