If your kids are well-behaved, though, don't rule out Jiko. This IS Disney World, after all, and kids are welcomed at (almost) all restaurants. We have taken our daughter at 4 and 5 years old to Jiko with no problems. They have the standard coloring equipment. We brought a few small toys for her and she was fine. She also enjoyed some of the more adventurous cuisine.
I haven't eaten at Boma, although I walked through and it looks very good. But I know Jiko to be an amazing restaurant, well worth it if the kids will behave themselves.