What a fantastic opportunity, go for it. I'd do it again in a heartbeat but DD1 no longer lives there, happily back in UK.
When you know your airline and the aircraft type/s you'll be flying on go onto a site called Seat Guru they give you a map of most airlines aircraft and show the best and the worst seats. Try no to get near the loos, even if you don't get any smells there is a lot of traffic so resting isn't easy.
I've done Emirates via Dubai and had to run through that great long concourse so going for assistance sounds like a great idea.
Flown with Singapore Airlines vis Singapore many times with stop offs and without. Love the swimming pool and the terminal hotels that can be booked for 6 hour slots. The massage chairs a great and if you are stopping over look on line to see what the airport has to offer.
I used to book a stopover with hotel slot and a full body massage both ways for most of my trips but it depends on how you book the flights.
Kuala Lumpur only once with a stop over, not my favourite routing.
Haven't done the new none stop flight so don't know but all of the above is good advice.
Hydrate, move, be comfortable, have entertainment, washing kit and change of clothes all good things and make a real difference.
Plus I still take my sweets and water. Airlines offer plenty of snacks and drinks but I like to have my own bits incase the crew are on a rest and the cabin is quiet.
I also fly with small first aid kit, headache tabs, tummy tabs, to helps to stop bloating, decongestants as I get sinus problems on long flights, face spray, a Pashmina, an inflatable foot rest (aircraft ones are usually in the wrong place for me) and a neck support.
Plus I wear support socks but the ones with holes in the toes and I always have an eye mask.
Only done business class a couple of times to and from NZ thanks to the frequent flyer program and it was such a bonus.
Think about what will make you feel most comfortable, what you'd like to have on hand while you are in your seat then go and have a really wonderful time.