If you are burning miles I'd recommend flying outbound on AC routing LHR-YYZ-LGA or EWR. AC's new 777-300ER aircraft begins serving the 1pm departure from LHR from next month and these aircraft will have the new biz class beds. On the return I'd try to snag a JFK-FRA-LHR routing with SQ connecting onto LH.

This would give you the best combination of comfort for your trip to NYC. Of course you may be more concerned with time for which there might be better options...