Farazi,
I can give you all the required details but I need to understand whih all countries will you be targetting.
One of the best ways to do this business is to use a surrogate carrier i.e. bounce calls to all countries from a pre-set and pre-installed location and just use a fat transit pipe to your gateway. ow investmend and low operational maintenance cost would mean low prices!
Kindly publish your contact details so we can talk real time.