OK ... READ those 4 vouchers carefully ... they are NOT 2016 balance due payment vouchers they ARE 2017 estimated payment vouchers and if you send payments with those vouchers the payment will be applied to the 2017 tax return and NOT the 2016 balance due.
If you asked for the installment plan you will get a letter of acceptance or rejection sometime after 4/18/17. In the mean time you can always make payments on your own to reduce the balance due.
https://www.irs.gov/payments