I never flew in EVA J, but EVA Y/Y+

1. It's Biz class, I think you'll be fine.

2. Y+ armrests do NOT come up and therefore not suitable when you have a row to yourself. It's better to go Y, or even 2 batches of Y and hope for empty middle seats, so you can lie flat down if load is light

SeatGuru map - I sure hope you get the newest 77N as old J isn't special
http://www.seatguru.com/airlines/Eva..._777-300ER.php