Aloha Richard,
I love the sound of your plan!
'Ohana is one of my family's favorite places to dine in all of Walt Disney World for a few reasons - the food is delicious, it's a fun atmosphere and the view of Wishes Nighttime Spectacular at Magic Kingdom is fantastic. The current pricing for the date you'll be visiting is as follows:
Adults: $40.46
Children: $21.29
Of course, prices are always subject to change, so just keep that in mind as you budget for your trip. Also, these prices include tax, but not gratuity.
'Ohana a popular spot to dine, so be sure to call (407) WDW-DINE (939-3463) or go online to make your dining reservations 180 days in advance for the best chance at getting the date and time you want for your special meal.
Wishing you a magical vacation, Richard! Please visit us here on the Disney Parks Moms Panel again if we can help answer any other questions as you make your plans.
Beth