sbs2716g: Yes, we are on SQ 32 as I wanted a direct flight. OK, we will prepare ourselves for PE. I'll go google some reviews.
onlySIA: very good advice and I agree, my kids are ridiculously lucky. I remember taking semi-annual trips to Asia with my immigrant parents in Economy and being absolutely miserable (despite being a kid and not my current 5'7" adult size!).
And yes, I also knew I wanted J class for the longer leg. I thought the SilverKris lounge at Changi would be incredible, so I'm actually glad to hear Polaris at SFO impressed you so much. I was quite pleased with the Polaris Lounge at LAX (which was 10 times better than the *A Lounge with its lackluster food and limited seating due to the hordes of passengers everywhere).
Thanks again!