I work at a company where I have been awarded RSUs that will be liquid at some point soon.

My understanding is that when I cash out I will be taxed on capital gains but also around 40% of the base price because it's taxed as a cash bonus, I believe.

So if I pay my tithing with those shares what kinds of taxes would I be liable for? Am I completely off the hook, or does it just count toward the standard deduction or what?