Public Accounting > 2nd Bachelors / Masters > Break into emerging markets?

Long story short; Non-target accounting grad who learned everything too late (3.5 gpa with 170+ credits); first job I'm taking is at a national firm in tax. I've interned in audit and don't like the mindless nature of the work. National firm is not as "prestigious" as Big4 but they offered more pay 1st year so that's why I took it. I will leap-frog into Big4 tax in a year if need be.

After two years of tax I plan to go back to school, as I don't plan on being an accountant longer than necessary. Worst case scenario is to do tax consulting. 

Options are:

- 2nd UG degree in engineering/economics at top 50 state school (I already have tons of transfer credits in engineering/math classes from being undecided in the beginning; would take ~2 years and cost less than masters anywhere else

- Masters in finance / masters in international economics, etc at T25 school (think UoM Ross, George Washington, UoT Austin, etc)

- Transfer internationally via employer?

Long-term goals: I'd like to get involved with the emerging markets via private equity or IB (My background is 2nd gen migrant from such a country; 2nd language spoken).

I plan to leave America in 5-8 years. Fantasize about working in Singapore, HK, Malaysia, etc.

I regret not studying abroad in undergrad...