I would probably not retake the GMAT if you have to still prep for it (which will take time away from the applications). The quant will be a concern at schools like Wharton and Columbia especially with your liberal arts background, but what at least helps is that you're in an analytically oriented job (banking and risk mgmt).
With Columbia, you really should apply ED (their round 1); same with Sloan (since they only have 2 rounds). Wharton, Yale and Stern (and any other school with more than 2 rounds), you can apply in Round 2.
So it's a tough one. I'd probably at least shoot for Columbia ED. Apply to Wharton Round 2 (since there's no difference in your chances between Rounds 1 and 2 in spite of what so many applicants each and every year seem to believe) - which will give you time to decide whether a re-take is worth it.