Vineet-
As you know, Investment Banking is one of the most competitive fields out there and financial firms will want to see high GMAT scores and grades, since they have the luxury of choosing from among the best and brightest. Work experience is actually secondary to the i-banking recruiters, since they like to train people from the "ground up" and make them earn their stripes in the field by slogging away crunching numbers for the more experienced bankers on the team. Having a background in finance, however can in some cases help demonstrate aptitude, but you would be better off if you could get that GMAT score up a bit. I am speaking mostly to the ibanking recruitment process than the admissions process, since your profile should be good enough to get you into a school or two on your list. The tricky part will come when you announce to the admissions committee that you want to do i-banking post MBA. They will scrutinize your plans just like the recruiters will and make sure you are competitive for these jobs. Getting some management experience at HBSC would be good and really the best thing you could do between now and application time would be to build relationships within the bank so you will have folks willing to go to bat for you not only as recommenders, but also as references when it comes time to get a job after b-school.
I am thinking of retaking GMAT which will boost my chances of getting into colleges of my choice and may help in future recruitments as well.