Flying to Hawaii, seating recommendations.

Flying to and from Hawaii from the NYC area, the plane for the trip is a Boeing 767-300.

I originally booked delta main for the seats, but considering the length of the flight I was considering an upgrade.

My question is which seating choice is the best bang for my buck? And is there any way to tell if this will be an older plane and if the accommodations are possibly a little outdated? Thanks in advance