BHF, I replied to your pm. the diamond is the only way to go. no swapping out limbs, simply adjust to whatever he grows into.
Well went went and he shot the Parker Sidekick XP for the hell of it, he loved the way the bow shot! He was shooting baseball size groups in about 6 shots, smiling the entire time!! I will admit that this bow really spit out the arrows! He is really looking forward to shooting the Razor Edge, we ordered it last week should be here tomorrow or Thursday, we'll shoot that and go from there!
My sons both have a Whisper Creek Phantom the draw weight is 10-25. They both just recently had me tighten them all the way down. It's been a good starter bow for them. I am pretty certain I will stay with Whisper Creek for them and step up to the Panther on their next bows. Its draw weight is 20-50. Then after that its up to them to buy their own. :d