Karen,
I got so excited answering your question for your large group that includes 5 boys that I forgot that you had asked for restaurant suggestions that were on the dining plan.
Here is a
link to the restaurants available.
While the Rainforest Cafe and T-Rex restaurant are not on the dining plan, a good idea at Downtown Disney would be Planet Hollywood which does participate in the plan as you can see by clicking on the link that I provided.
Some other ideas would be:
Coral Reef Restaurant
Wide World of Sports Cafe
'Ohana's Best Friends Breakfast with Lilo and Stitch
ESPN Club
My son might not admit it but he also loves dining at Cinderella's Royal Table! It might be the souvenir sword or the princesses addressing him as Prince. He also likes being asked how many dragons he had to slay to get his family to the Castle.
I truly appreciated this follow-up question and hope your family has an amazing time in WDW!