Thanks for sharing your profile, it was an interesting one to read. On one hand, you have a lot of common experiences and profile attributes among MBA applicants (IT and Engineering background, Indian nationality and undergrad, financial services background, lots of quant and technical expertise), but you do have other aspects that help you stand out some from other applicants with those attributes (such as your US/Big4 NYC work experience and US Masters degree; your education/time in Hong Kong; your travel around the US and world; your extensive accomplishments at work and your teamwork experiences).
Overall you have a strong profile for the schools you mentioned, and it sounds like a lot of great experiences that you could use in the application essays as well as in the b-school classroom itself.
One piece that is missing from what you provided so far is-- WHY. Why do you want the MBA? What are your short and long term career goals? Do you need another Masters degree? Etc. If you can create compelling essays to answer those questions, your profile will be strong, with the biggest weakness being the GMAT. LBS will be the biggest reach from your list because it has the lowest acceptance rate, but it is also a popular program for those with a finance background (which is a plus since it could be a good fit for you, and also a small minus because it means you'll be part of a large group of applicants with finance experience). In summary I believe you have a chance at the schools on your list presently, but it would be greatly increased with a higher GMAT score, yes.
If you decide to re-take once more, I encourage you to seek help if you haven't yet-- with GMAT preparation or a tutor. It sounds like verbal is the biggest challenge for you so focus a lot on that side. Usually if you are able to break 700 on the software you have the ABILITY on test day as well, but maybe you get nervous (??) or your timing is off or something is different on the actual exam, so a tutor or class can help you identify what is going on and break through that barrier if possible.
Hope that helps and let us know how everything goes and if you have any other questions!
mbaMission Insiders Guides: http://www.mbamission.com/guides.php?category=insiders
Free Consultation: http://www.mbamission.com/consult.php