How about the Wheel Vintiques Billet solid or gennie wheel. I'm not sure what the weight difference would be between the steel 17" and the aluminum 18". You can get them up to 18x9.5" and if you powdercoated the whole wheel they would look like a stock style steel wheel. Most of the caps that they make for them look a little too old for a '67 model, but the ones below might work.
I wanted to use these on my '52 Chevy pickup, but they don't make any Chevy caps that will fit these wheels
You sure you don't need a '62 Falcon too! - J/K
Later,
Brandon