Specialisation in US/canada after MBA

Hello Sir/Mam

I have done MBA(finance) from IBS (Hyderabad, India) and have been working for 3 years in my family owned real estate business as a project manager. Now i am planning to do specialisation(MS / MBA) in International business mgmt in US/canada and after that want to work there for 3-5 years before starting my own import export business in india. Pls throw some light on following:

-> Is it fine to do specialisation after already holding an MBA degree?

-> Career prospects in International business mgmt?

-> I shall do MS or MBA?

Looking to hear from you soon.

Thank You