Hi zuko23,
First off, a 750/Q48 is an outstanding score (it's well above the 90th percentile overall), so you should apply to any Business Schools that interest you. In basic terms, Business Schools don't put too much of an emphasis on the AWA score; as long as you score a 4.0 or higher, then you should be fine. With a 4.5, you shouldn't have any issues there. All things considered, there's no obvious reason for you to retake the GMAT.
You're ultimately asking Admissions questions though, so you would likely find it beneficial to speak with an Admissions Expert about your overall profile. There's a Forum full of them here:
ask-admission-consultants-124/GMAT assassins aren't born, they're made,
Rich