From someone who has flown the same exact route as the OP for many many years, I would say that you should focus on multiple frequent flyer programs, namely AA and UA (if you can bear flying into EWR). Why? So that you have options in terms of pricing and flight availability.

For AA, like someone had suggested, those 767s have plenty of "couple" seats (2+3+2 seating is great) and service is not bad. Getting both Citibank AA credit cards (50K miles each, or has the offer been devalued a bit?) is what you really need to do to maximize your miles.

For UA, get their credit card for 50K miles (really can get 60K but that's not worth it) and the Chase Sapphire Preferred (50K points transferred to UA as 50K miles). That's 100K miles with very little work (easier than AA)