tbone,
here is a site that has a list of all of the Smart and Brabus wheels, their widths, offsets, PCDs and recommended tire sizes:
Evilution - Smart Car Encyclopaedia
I do believe it is sort of sectioned off. Most of the information for 451 and forfour (454) wheel information is at the bottom. The bulk of the list is 450 wheels.
Any time you want to know anything about the 450, just go to the model go to the Smart Car Model Discussions -> original smart fortwo section of this forum. Tons of knowledge already catalogued there.
http://www.smartcarofamerica.com/forums/f26/