Jerry, with due respect, if you haven't experienced these harmonic vibes, you really don't know how difficult a problem it is. It's not a simple pinion angle or driveshaft balance problem. I've spent the last 5 months dealing with it and trying a LOT of things (just ask Dave Kishpaugh). Scores of forum members including @bobthetj03 @Mr. Bills @Chris and myself have been trying to figure it out.That's the first time anyone has mentioned a front-end vibration strictly from the choice of 5.13 gearing in any of the several Jeep forums I follow. Any vibration is more likely from an improper front pinion angle than the actual specific 5.13 gear ratio itself. When that's the case it can usually be dialed out by correcting the pinion angle. I wouldn't hesitate going with 5.13 at all for 33" tires, I went to 5.38 for my 35" tires.
Deeper than factory gearing somehow brings the problem to the forefront in some jeeps. People have reported issues with 4.56/4.88/5.13/5.38s. In some jeeps, locking front hubs is the only solution. In others, like mine and @bobthetj03's, even that doesn't work.
Please don't trivialize this problem. Your advice for gear choices is spot on (maybe on the deeper side, if any), but please note that regearing TJs has an inherent risk in terms of introducing harmonic vibrations. For some of us, there is no free lunch.