I went to Hawaii in Sept. It was very nice. I suggests that you check www.fodors.com`s tavel talk. You can get some great info. I recommend you tryKAKA`AKO KITCHEN Ward Centre, 1200 Ala Moana Blvd., Kaka`ako, It is near Ala Monan Mall. It is good food in a box.
Speaking of BBQ, it is considered Hawaiian traditional food. If you are hungry, you can try a local chain fast food. It is called " L & L Drive Inn". It offer HUGE portion and very good BBQ. Warming: Regular portion is very big.