Although I didn't fly the JFK-Sao Paulo segment, I flew NRT-BKK on the aircraft using the SkySleeper first class. On the overnight flight I took the aisle seat. If you are in the window seat and the aisle seat passenger has the seat all the way down into "bed" mode, it is very difficult if you want to get out. I would also recommend rows 2 or 3 over row 1 as row 1 AB is very close to JK seats. They did bring the food carts up to that area. You also don't have overhead bins over row 1, but there is plenty of bin space & storage available. JAL flight attendants actually help people store their carry-on luggage.

First class always had the noise reducing headsets and the menu selection was more extensive with service whenever you wanted it. Ask for the first class pajama sets - much more comfortable to sleep in than your clothes.