Until recently Swipe Pro was the choice for in US transactions and iSwipe global was for international. 

As of it's newest release (version 3.4) Swipe has taken on all the international capabilities of Global.  Swipe now has the ability to select the country code it's operating from and to set the currency type.   Altho iSwipe Global will continue to function and will be supported, our intention is to phase it out, leaving Swipe Pro to neatly fill the roles of both.

So, from this point on, the answer to the question "Do I need Swipe Pro or iSwipe Global?" is "Swipe Pro without a doubt, no matter where you are"