Rabbits for children
There are several breeds that could be considered - the mini lop, dutch, rex.... but the best thing to do is to get a rabbit from a breeder that really cares about their bunnies. This will ensure that the bunnies have been held daily (also correctly) and are not afraid of human contact. Good breeders will also make sure that they breed healthy rabbits with good temperments. In addition, you can meet the baby bunnies parents and check if they are friendly before you buy. I recommend www.mybunnykingdom.com in Kent (England) - fantastic gentle mini lops! They are so, so beautiful!
The mini lop is a breed known for its fun personality and gentle lovable temperment, but please remember that bunnies need a responsible adult owner who will ensure they are respected by the young child. Too many parents do not supervise their children whilst they pick up/ play with bunnies and then wonder why the bunny suddenly starts biting or being aggressive - blaming the bunny for the behaviour.
In addition younger owners will rarely continue the care needed daily to ensure rabbits are looked after properly, despite their begging and promises that they will, so the adult needs to be prepared to work and take on the care themselves! Taking in a bunny should never be considered if the child's parent is not committed too. Further, if you buy a bunny for your child, you need to find out as much as you can before you buy about how to care for your bunny.
To conclude, rabbits make the best companions for old and young alike and many breeds can be wonderful for children, with commitment, respect and kindness at the forefront of the bunny owners (and parents) mind.