None of these are great. JFK airport hotels are mostly pretty miserable, even if just for a quick 1-night stay.

Delta has the advantage of being in the same terminal as EK at JFK but you still have to clear customs and reclear security, and the security lines at JFK T4 in particular can be very bad. Plus, if you are checking a bag, Delta has a strict 60 minute bag check-in deadline at JFK. JetBlue's terminal can likewise be pretty chaotic.

So probably have to go for the hotel in my opinion.