Looking for Advice on a new Tow Vehicle

I tend to think you're better off with a solid front axle on a HD truck if you ever take it off road, but if you're just using it as a tow vehicle and won't ever stray far from pavement you may actually be better off with IFS. If you do plan on driving the truck in rougher terrain there are some things you can do on the GM front ends to beef them up, but you'll still have the inherent limitations that go along with IFS in rough terrain.