the second recordset should contain the email address and you should set Universal email up to loop through the that recordset to send the email.
then in the email template file, add the following code at line 1:
<?php
global $RecipArray;
global $RecipIndex;
?>
Now in the body you can reference columns from the recordset using:
<?php echo($RecipArray[$RecipIndex][0]["[yourColumnName]"]); ?>
where [yourColumnName] is the name of the column from the recordset you want included in the email