Welcome to FlyerTalk!

First of all, the 2-hour stop in NRT is like a regular connection. You deplane and reboard the aircraft. It might not even be the same aircraft, so don't leave anything behind.
As for EC, I would buy it. If $159 sounds expensive to you, check to see if you can upgrade only NRT-JFK, as it is longer. However, I don't know if 1-stop direct flight can be split into segments for EC purchase.
24D-G are also bulkhead, essentially with unlimited legroom, as the wall is really far. However, the armrests are immovable, there is no storage space, and because of the large gap between the seats and bulkhead, people tend to stand there or cross between the aisles. Other EC seats have enough legroom, if you're not too tall.
As for drinks, wine and beer are free in regular Y, and EC gets free cocktails.

Enjoy!