You have made a good start because you are looking at your options.
Because you know that if you do nothing you will have a big tax bill in April 2017, you want to make sure that you avoid the underpayment penalty.
One way to avoid it is to make estimated payments. But even if you do that you could still make a mistake and overpay or underpay.
I think the easiest way to handle it is to reach the safe harbor. If your withholding from your regular jobs and any estimated taxes you pay in 2016 equal or exceed your total taxes for 2015, then even if you owe a lot in April 2017 you can avoid the underpayment penalty. If you AGI is over 150K you have to make sure your withholding is 110% of your 2015 taxes. Then set aside what you think you will owe in your bank account until you have to pay your taxes in April 2017.
You only have to adjust your withholding to make the safe harbor. You can make sure easily enough once your file this years taxes. You only have to make sure that you reach the 100% or 110% threshold.
From IRS PUB 17
Who Must Pay Estimated Tax
If you owe additional tax for 2015, you may have to pay estimated tax
You can use the following general rule as a guide during the year to
see if you will have enough withholding, or if you should increase
your withholding or make estimated tax payments.
General rule. In
most cases, you must pay estimated tax for 2016 if both of the
You expect to owe at least $1,000 in tax for 2016, after subtracting your withholding and refundable credits.
You expect your withholding plus your refundable credits to be less than the smaller of:
a. 90% of the tax to be shown on your 2016 tax return, or
b. 100% of the tax shown on your 2015 tax return (but see Special rules for farmers, fishermen, and higher income taxpayers , later).
Your 2015 tax return must cover all 12 months.
Estimated tax safe harbor for higher income taxpayers. If your 2015
adjusted gross income was more than $150,000 ($75,000 if you are
married filing a separate return), you must pay the smaller of 90% of
your expected tax for 2016 or 110% of the tax shown on your 2015
return to avoid an estimated tax penalty.