My wife is currently freelancing, and the IRS would want us to file and pay estimated taxes every quarter, which is a pain. I could take extra deductions out of my paycheck, but figuring out the additional amount to withhold is a bit of a pain to.

Preferably I'd stick roughly the amount of taxes due in a savings account each month and pay all taxes when we file, but read there could be a penalty if you owe money at time of filing.

So, should we bite the bullet and go with the quarterly filing, withhold extra from my paycheck or save the money and pay when we file (preferred)?