Chris,
I think maybe you are the only hot rodder running a slant six. I know a slant six is a hard engine to kill but it can (and should) be done. Before that sweet little girl is old enough to know what a V8 is. The bumpers you're looking for are the same as a Barracuda so if you find them they'll be expensive. The good news is most high performance parts for a Barracuda will fit your car. Find a good Hemi or 383 or even a 318 to put in it and you're on your way to being a Mopar type hot rodder.
AL