Unless you require a major suck-up, as in Richard Gere's remedial advice to Rodeo Drive shop assistant in film Pretty Woman, during your trip, Business Class will improve your experience so much in all the ways above that the extra expense of going First is mostly unjustified.

First is a real experience mostly on the Asian carriers.. Singapore Airlines, Thai... Cathay.... etc. Not always on most US carriers (sorry, US carriers!) and not on all the European carriers either, with some notable exceptions.

I recommend Business Class for your trip,and depending on the time of year there may be lower-price offers around on some Business Class routes too.