Reaseyann - If you manage this trip to your abilities and to the abilities of your scouts, you should be fine.
I have backpacked into the canyon 4 times. Each time was different. All good experiences. I have never backpacked there in the summer - mostly March / April.
Judging by the experience level you have indicated, I would stick to the main trails (Rim Trail / Bright Angel Trail / South Kaibab). These are all well travelled and patrolled by rangers.
As someone before mentioned, a hike down the Bright Angel to 1.5 mile resthouse might be doable. Allow about 3 hrs ro