Dexstar wheels would be a good compromise. They have 15x6 and 16x6 wheels.

http://www.dexstarwheel.com/products.pdf

http://www.etrailer.com/Tires-and-Wheels/Dexstar/AM20514.html

You can try the Wheel Smith. Might be a little pricey though.
http://www.thewheelsmith.net/

There's Wheel Vintiques too. Again, may be a little pricey.
http://www.wheelvintiques.com/about-us

1954 3600 Chevy Truck
"The Fake Truck"
In the Stovebolt Gallery
More pix on Photobucket