On the one hand, lifting a truck will hurt the towing dynamics. On the other hand, you're talking about only 5K pounds with a truck that should be good for twice that or more, so you aren't really pushing it. My gut feeling is that it would be fine, but unless you want the lift, I'd prefer a stock height one.
I've thought about going the other way. I can't help but think my truck would be way cooler dropped about 6" on some 20" rims. But that would mean spending money that would otherwise go to the racecar, so instead it rolls stock.