I'm not sure how much help this will be but on 747's I think the 2 ?? 2 rows are the best (well the 2 person rows are) and when flying in economy request them but never the last row at the very back. Some planes have toilets there and people loiter and lean on the back of your seat. The 4 in the middle are not the best you want the ones next to the windows. I'm presuming a 777 is similar but one of the others will know. I've never flown in economy on a 777.

There are a few other seat guide site that may offer some more advice. Enjoy your trip.

I'd ring up emirates and say your on honeymoon and request something simple like champagne...this might just possibly trigger an upgrade to business. Somewhat Unlikely but possible! Also mention it at checkin. The MAN dubai route is busy so you may not get it but you never know.