I just flew TG922 in C. I would vote for row 16 and being across the aisles from each other in A/D or G/K. It doesn't show on the
SeatGuru 9W chart for the plane, but 16's seats are considerably more private because of the bulkhead- you also get a bit more storage space. 16A (my seat) sees into 16D (across the aisle), but not really into anyone else's. G and K should mirror it. You'd be able to converse without stretching a neck.
I actually rather liked my seat- didn't feel very claustophobic, "coffin" like at all. Heaps better than the OZ C or older TG C slanty flat seats I flew in in earlier segments (and I imagine the LH C seats I am about to have on the last segment). That being said, if TG does their new seats right on the A388, they'll be pretty good...