DX3e and DX3R depending on your budget mate. My kids have both, Jake started with the DX3R and has been using it for 2-3 years. He is turning 8 in May. My little girl is not 5 yet and she uses the DX3e.
The only thing that might be a problem is braking. At first I started them on using quite a bit of drag brake but they would nose dive every time they jumped. I took that off and modified the trigger with an extra bit of fuel tubing so their fingers touch the front of the trigger. Now they can brake too, not that they bother to though
