Tips for possible career direction?

I am currently 19 going into my junior of college and I recently switched my major to Business Management; my school does not offer a masters only a BA in Business Management. I have also begun and internship at an accounting firm in which my boss has suggested to me I go into Sales and Marketing. So far I have basically been apprenticing my boss and learning how to create relationships with different clients, database management, how to prepare presentations, and how to work microsoft excell properly. I really like what my boss tells me about sales and marketing, I feel like I have the personality to excell in the field, and my boss feels the same as well. I have asked my boss before if I should get another degree in business and he says absolutley, I just want to here some other opinions. I know that I need a MBA in some field of business, I have been thinking about doing finance after I graduate but I am still unsure. My question is, with a BA in Buisness Management what would be the best degree to attain along witht the BA in BM, in order to better my odds of getting a good paying job out of grad school?