Since it is after December 31, 2016, a SIMPLE IRA deduction is not available to you for 2016 - this type of account needs to be established and contributed to during the tax year to which the deduction would apply.
You are able to open a SEP and contribute to it until April 18, 2017, to reduce your 2016 tax liability. You can then (at the same time, if you wish), establish a SIMPLE plan for 2017.
You should consult with your financial institution about whether they will require you to use a business account to fund the plan, or if you can use a personal account.
