Derek,
If you fly LHR-JFK a fair bit and can rack up 25k miles in a calendar year there is a carrier which will automatically put you in a seat towards the front with around 37" of pitch, and also automatically block out the seat next to you until it's absolutely needed. All on the cheapest ticket too. Unfortunately their planes are on the N-register, and you don't do that
, but then your loss is my gain as I don't have you taking that blocked out seat next to me. (Not that it bothers me, as they will usually (>50%) op-upgrade me if the flight is that full)