"...vs just having another $800 deducted from my paycheck semiweekly"
Why does it have to be $800? You can enter any additional amount you want withheld on Line 5 of your NJ-W4.
https://www.nj.gov/treasury/taxation/pdf/current/njw4.pdf
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
