You are applying from a very deep applicant pool, but your work experience is not the most common, which should help you differentiate yourself. I am concerned about your academic record. Top b-schools want you to have demonstrated success in the classroom, so a good GMAT score will be critical in counterbalancing this shortcoming. I also notice that you anticipate getting a higher score on the actual exam than you have been getting in practice. This is not generally the case, so make sure you work hard to approximate the testing environment before sitting for the test for real. It sounds like your post MBA vision is not completely fleshed out. This is a critical and very oft botched portion of the application. B-schools want you to have figured out what you want to do before you go back to school, so you should hone your vision a bit more and present a unified plan to the adcoms which leverages your past experience with your future career. Let us know if we can help you pull everything together. I think you could indeed find a place in the top 20. Applications are down this year and international applicants are an important piece of the puzzle for schools who like to diversify their student body.