Novice Fliers - A340-600 Economy Seat Advice Please

Hello all,
We've never flown longer than four hours before but will be on an A340-600 from Boston to Heathrow later this year.
It's just the two of us and my wife wants a window seat.
She wants to be on the left hand side of the plane.
We are quiet people.
I am looking at 41A/C or 42A/C because the stairwell means a blank wall or door(?) next to us rather than other people.
The problem is that the various seatplans differ slightly so that I'm not sure which row or rows have the stairwell.
I'd be grateful for any advice re these seats or others you might suggest as quiet.
Thank you.
Jerry
We've never flown longer than four hours before but will be on an A340-600 from Boston to Heathrow later this year.
It's just the two of us and my wife wants a window seat.
She wants to be on the left hand side of the plane.
We are quiet people.
I am looking at 41A/C or 42A/C because the stairwell means a blank wall or door(?) next to us rather than other people.
The problem is that the various seatplans differ slightly so that I'm not sure which row or rows have the stairwell.
I'd be grateful for any advice re these seats or others you might suggest as quiet.
Thank you.
Jerry