Rule #1: DO NOT RELY ON SEATGURU. That site hasn't been updated in forever and the information there is at best outdated and at worst misleading and inaccurate.
There's two ways to survive a flight this long in EK Economy:
Depending on how full your flight look to be, select any aisle seat in the middle section towards the back of the bus that has no other takers and hope that this stays that way. so you can stretch out across the whole row for the EconomyClass lie-flat experience.
If the load is high and that's not possible, 68AK or 81 AK is the place to be in Emirates A380 Economy. Caveat: I`ve only ever taken Emirates flights as Qantas codeshares booked through them. As I have top tier status with oneworld, those seats were accessible without a fee for me but that may not be the case for everyone.
Read some seating threads in the EK forum with advice on how to 'seat hopping' via the app between check-in and boarding and get the nice seats for free:
The ultimate Emirates seating guide
Emirates economy seating strategy