So you want a 17x17 steel wheel?
I've never seen such a thing and the weight on them is going to be just like their size: enormous. This is going to be a specialized, custom build.
Even in 15" diameters, I don't think I've ever seen a 17" width. It just an oddball size. I have seen 15x12, even 15x14, but never a 17".
In Nascer styles, 15" diameters are the norm as that is what the sanctioning body rules require. The only time I've seen a 17" diameter nascar style wheel was on the Ray Evernham '64 Plymouth build, and those were one off custom units that retained the Nascar spec 9.5" width.