17x8 245/45/17 on all four with 4.5bs?

The 5.72 backspacing is what is run from those that have "found out". It is what it is. Unless your getting some kind of special deal, I'd stick with what works.

Good Luck.

not without at least a 3/4" spacer on an A-body rear end. 5.72 bs on the front is fine, but to avoid spacers you would need a B-body rear.
Ideally, a wheel with 4.75 to 5" bs would work on an A-body rear end.