My first time flying on United long flight ( SFO ==> SIN==> PNH ==> BKK ) and I have few questions, can someone please help :

1) For SFO - SIN segment, flight # UA29, Boeing 787-9 Dreamliner . United website indicate this flight ( SFO -SIN segment) has Polaris business seat. How do I check whether my flight is a Polaris business class or just a normal business class.

2) What row # has best seat to choose for a couple . I look at the seat map but unable to tell which seat ( D & F) to choose . I prefer the odd seat number, seems it give more privacy and can lie down with straight foot .

3) Does United offers in-flight amenity kits ( Pajamas , slipper , eye shade, mattress cushion ect...for business passenger for long flight . I read online that I must ask for it early on the flight because it may run out. is it true

Please advise and thank you.