You're right, you will need two specifications - one for the check with an advice section that will say something like "As per attached.", and another for the 8x11 advice. After the checks have been printed, Adagio asks "Do you want to print additional forms?" if this option has not been turned off for the bank. The user selects "Yes", and then prints all he required advices.

It is easier to manage these high volume vendors if you place them in their own report group or control account. Then they can easily be selected for processing.