The seats recline 6". I am 6' tall and have more than enough leg/knee room with the seat in front fully reclined. Just a personal preference, I would take the back row over the front. In the front you have the TV screen that folds down and no under seat storage.
Another option is to book economy and pay extra to move up to the main cabin extra seats.
Go to Seat Guru to see the specs. for the various seats. https://www.seatguru.com/airlines/American_Airlines/American_Airlines_Boeing_777-200ER_E.php