I'll be traveling SIN-AMS-LHR this September and it will be my first long-haul trip. I have no choice but must fly with KLM and noticed that the Economy class seat pitch is 31". Sounds uncomfortable already.

Should I even attempt to purchase an Economy Comfort or seat with extra legroom?? Any idea how much it would cost for the route?

With the 31" pitch, is it even possible to sleep on board the plane?

Details I have are
SIN-AMS (777-300 or 777-200)
AMS-LHR (737-800)

A bit nervous as I am used to the 32"-33" pitch with Asian airlines, and most recently, a ultra-comfortable 42" seat pitch with Thai.

Appreciate any advice anyone might have!

Thanks!!