Front Rubbing - Tires, Suspension or Wheels?

If anyone has any input on wheel/tire sizes, I could use some help filling in the blanks.

For the front I'm thinking a 17x8 with a 245/45, but what should my wheel back spacing be? 5.0, 5.5, something else?

For the rear, I am even less sure what I need. I think I'd like to stagger the sizes and use an 18 in the rear, but the width, backspacing and tire sizes I'm not so sure about. I have relocated springs, but stock tubs and I definitely want it to sit much lower than it does in the above picture.

Could I run a 275/35/18 on a 18x9.5? If so, I have an A body 8.75, so what backspacing would be appropriate? Is a 275 too wide? I know the 295s I have now are.