Should I submit the IRS ACH payment form with NO PAYMENT info, is that how I get the 6 month extension?

when you request an extension you're expected to pay the full balance.
go to www.irs.gov/payments and "Make a payment"
select Reason:  Extension
any payment is sufficient ($5.00  will do). approval is automatic

Make a note of your payment  amount so you can claim credit for that when you file.