I would instead suggest finding flights that are almost empty in coach, so that one can stretch/spread out. If the flight is full and one does not get an op-up, one can be in for a very unpleasant experience.

I did 13 transatlantic segments in 2003, 11 of which were in Y, including LHR-ORD, DFW-LGW and ATL/CVG-LGW (all longer than the short NYC-London hop). One flight was an op-up to J, and one was F, both AA. The most enjoyable flights by far were those that were less crowded in back: better and more relaxed service and I could usually commandeer the adjacent seat (I don't like to lie across multiple seats, though many do). The flights that were full were tolerable only when I had an exit row (status matters), excepting the op-up to J (and which was then also full, meaning that service was the minimum acceptable for J).

More practically? Whatever makes you relax and think that you are somewhere other than a cramped airline seat. For me it's a good book and as much sleep as possible (I pick flight times that are likely to be when I am most amenable to sleeping), plus a drink. I would think not in terms of how to replicate F/J, but how to make the experience in general as pleasant as possible.

[This message has been edited by chalf (edited Jan 16, 2004).]