In SQL an array is modeled as a Table.

Parameters to a stored procedure are more like arguments to a method in C#, however there is no concept of overloading in T-SQL.

Starting with SQL 2008 you can pass tables to a stored procedure as a parameter, lookup Table-Valued Parameters for more info there.

You never told us whether the destination of your flat file and the SSN data are on the same instance, or different instances.