My vote go for buying Soraben at Haneda, no point of buying Ekiben at a train station before getting to the airport. Yes, shopping area before the security has more choices by I found Soraben selection after the security to be fine for me. Usual Makunoushi (幕の内) type bento, find good selection of meat type of Bento. Also there are selections of sandwich, including Katsu Sando (カツサンド). On evening flights I often buy Soraben at gate area of Haneda airport and take it to my destination when at the time of arrival it is late at night,

On OKA flights on JL they sell ice cream for 300 yen. Also, for you and your hubby OKA flights sell Okinawa beer (Aoi Sora to Umi and Orion) for 500 yen which comes with small bag of rice cracker or other type of snack.