72 dart backspacing question

OK so if I decide not to change anything I will most likely go with Coy wheels because I like the look and they offer 5x4 bolt pattern. I am considering that or

In a 15" wheel the 15x8 comes in a 4", 4.5" and 4.75" back spacing. Guessing I would need to go with 4.75 if I keep my a body 8 3/4 rear end as is. Is that correct.

The 15x7 only comes in 4" backspacing. Will that work on the front or would I need to go to a 15x6 which has 3.5" backspacing?

Basically I am trying to decide if I want to keep it as is or start making changes to allow me to run a little bigger tire.