Welcome to a public forum. You're going to get opinions whether you want them or not.
Your question was:
My answer is NO. Because of the safety factor that these parts are designed to, it's unlikely that you have a lot of room for play without putting yourself and other peoples safety at risk. I personally think that anyone who grinds down their brake calipers to fit different wheels on a vehicle that's driven on public streets is a complete idiot and i pray they never fail and hurt anyone. There are plenty of other ways to make your vehicle "stand out" that doesn't require high risk. That's my opinion, take it or leave it.
As far as your second idea is concerned. I'd just go to a parts store and have them pull out a caliper assembly and rotor for both trucks and compare them to see if they might bolt up. Still taking a step back in terms of braking performance (which i'd probably laugh at anyone when they told me they did that just to fit 1" smaller wheels) but at least the parts aren't hacked from their OEM configuration. Throw some SS brake lines on there to help keep the pressure up while you're at it.