Here's a comparison shot of 15x8 w/ 4" backspace and 15x10 w/ 4" backspace. Both on 12.50 tires. With the same backspace, the 10" will stick out 2" more.
I know you girlie...you won't like the 10's because you like your paint. hehe.
If my truck had less tire to fender clearence, you'd be able to tell better.