Take a look at Maddog bows by Mike Mecredy. He is a tradgang sponsor and makes great bows for a very reasonable price.
This is my 13 year old son with his new birthday bow. It is 42 @ 28 and 60" long. He is drawing about 26", so holding around 38#. Mike said this 'midsize longbow' can be drawn out to 30" so it should last him a few years.
His last bow was a one piece Maddog midsize longbow, 56", and 32 @ 27. He was almost maxing it out with his draw length so it was time for an upgrade.
This is a great bow for him. Very light in mass weight, good size grip for his hand, good looking, good shooting, and one that he can grow with for a few years.