I think novanative hit it right on the head. I think you need to decide between full time and part-time and that will inform as to whether or not you retake the GMAT. For PT (which tends to be less competitive) your score and GPA combination are certainly good enough. While as was stated you come from a well represented pool, I'm not sure how much this matters for PT. Most students in that program will be working for large corporations or in consulting as those are the companies likely to reimburse tuition and are companies where an MBA may be needed to advance in one's current company. PT really doesn't cater to non-traditional applicants.
If you want to change careers FT is the way to go. Moreover, if you want to change companies, the FT recruiting process is much more conducive to this.
For FT, while your score is still within the 20% to 80% range of most schools, it seems like 700 to 720 is the magic number for schools to "check the box." If you scored a 670 in two weeks of prep, you should easily be able to achieve that if you spend 6 to 8 weeks. I would encourage taking the test again as you will likely do better and the last thing you want to do is leave something on the table of your application.