As much as people (and Adcoms) say that GMAT is only one part of the application, I personally believe that in 2009, you probably want at least a 700 GMAT score to avoid disqualifying yourself from the Top 10 schools.
A WL at Kellogg is a great feat in itself, so don't worry too much about it. Looking at your simple profile, I think you have what it takes to get into schools like Kellogg, but either your essays or your GMAT is holding you back. Of course, without knowing what you wrote for your essays, the GMAT is the only thing we can give you opinion on.

As for taking it a 4th time, ONLY do it if you have consistently scored high on the Quant side. Otherwise, you'll probably end up with 650 again.
I highly recommend the GMAT Club math tests or the Manhattan CATs. The math is BRUTAL and way harder than the actual test, but if you can learn to time manage your Quant on those tests, then you'll find the GMAT Quant section to be super easy. That was my strategy and I could not believe how easy the actual Quant section was when I took it.
Good luck no matter what you decide!