Why not create a Script Task in VB language within an SSIS package, that runs the LDAP query results either into a SQL Server table using ADO code, or into a text file, which can then be imported to SQL in the same package...   That might get you away from the ADSI limit.   Not sure if using VB to run the LDAP query will have the same limitations or not, though.   You'll just have to try...