Rim width and backspace

Hey guys.
I am looking into getting these rims for my 1974 Duster.
I am getting 17" which I assume fits.
What width should I go with? Same on all four corners? Or wider in rear?Comes in 7", 8", or 9" width.

What about backspacing? And bolt pattern?

All the specs for this rim are here:

American Racing : Wheel Specs

Any help would be great.
Thanks!