eh, my F*rd pickup truck makes a noise just like that and I've been shafted by so many shops I've given up on it. (wanna buy a truck? Seriously, soon as I get the Jeep sorted, it's GONE. I have literally put more than the value of the truck into having people misdiagnose the problem and replace stuff that has nothing to do with the issue.) The ONLY thing related to the front end that isn't brand shiny new is the spindles themselves (well, and the I-beams, but they couldn't cause the noise I'm hearing.) So my amazing powers of deduction tell me that one or both of the spindles must have been worn by bad wheel bearings in the past to the point that the rotors wobble as they turn, causing that obnoxious noise.
So... question is, have you checked your hub assemblies for play?