Wheel backspacing to make not rub springs

[Behr]

im looking at a new set of rims for my 04 and ive got the stock 16x7 rims and im running 315x75x16 toyo mts and the tires rub when i turn all the way, im looking at goin to a 16x10 and a 38x13x16 tire and i dont want them to rub cause it anoys the crap out of me. the rims im looking at have a -38mm backspacing is this what i want or what backspacing would be best ive got bushwacker cutout flares so i dont have to worry about goin to far out. any input is greatly appreciated

[Behr]

these are the wheels im looking at ull have to click on the attachment as i dont know how to put pictures on here yet