Form 1040-ES has a worksheet that will walk you through the process of figuring out your estimated taxes--it's fairly straightforward.
SS and Medicare taxes do not figure into estimated taxes, as they are part of the payroll process.
Edit from comments
So the 25% federal bracket, does that not include SS and Medicare
then?
Correct, your federal tax rate is completely unrelated to payroll taxes. Everyone pays the same rate, regardless of tax bracket (although SS tax maxes out at a certain income level).
Are you saying I should estimate the payments on the full 25%?
Hmm, I'm actually not sure what you mean by "the full 25%"? But it's actually simpler than you're making it, I think. If your income will be $80K this year, use that number as the starting point for filling out the worksheet. That amount will be income regardless of whether it is payroll or distribution, and should be the basis for estimated tax payments.
Note that this assumes $80K is your net income--revenue minus expenses. Expenses will include employer-paid payroll taxes (for your and any employees).
I'm using intuit payroll for myself and my employees.
I use a different payroll provider, but assuming intuit is similar, they should be withholding the correct taxes from you and any employees, and also making the quarterly payments for both those withholdings and your payroll tax responsibilities (as the employer).