Last year we took our kids, approximately the same age, to Bangkok and Phuket. It was still Asia but very manageable, terrific sights (Bangkok is fascinating), great great food and incredibly nice people. We thought it was a terrific destination. And, you can travel there as upscale or not as you like. Just make sure the hotels you choose have a pool, if possible.

We are trying Bali this year, which is also another option for you.
Have fun.