BIGBET-
You know you have three options available to you regarding thest payments.
1. Pay 1/4 what your estimated yearly taxes are in quarterly timed payments.
2. Pay in full at anytime(although your money will not be working for you, you know you are paid and done with).
3. Not pay ANY quarterly payments and accept the penalties on your next years taxes. (Sometimes this penalty can be very small and if your money can be making more in the previous 10 months than your penalty, you may want to choose this option..........however it POSSIBLY may raise more red flags in my opinion).
Again, EVERYBODYS tax situation is different, so no way can anybody on a forum provide PERFECT AND 100% accurate advice without knowing the others complete financial landscape of earnings, investments, residence, types of income, etc., etc............so therefore always find yourself the best tax advisor you can find.
-Fish-
ps- Bigbet, know you know most of this allready probably, just stating for others more than anything else.