There are different numbers depending on whether or not you have the towing package (auxiliary cooler)
With the towing package: Auxiliary cooler - 12364240; cooler to radiator pipe - 25615308; cooler to transmission - 25606751; lower pipe - 25615305.
Without the towing package: Upper pipe, cooler side - 25606750; upper pipe, transmission side - 25659161; lower pipe, cooler side - 25615305; lower pipe, transmission side - 25615306.
This is from an older parts list, so it is possible that there has been some changes. Perhaps you can check with the dealer to double check all the numbers.
It appears as if http://www.rockauto.com/
ships international orders. I don't know if they will have those parts or not.
This is another dealer based parts supplier (like GMPartsDirect) that also appears to ship international orders. Their prices are generally a bit higher, however.