New bed for ds, 11 years old

[admylin]

Ds is in need of a new bed.

He's on a matress at the moment and thinks it's great and wants to stay that way but he does need a bed.

I've looked around but can't decide, should we get him a big nearly double size bed already or a normal single? I suppose a futon would be OK too. Any tips?

Ds is 11 by the way. No ideas yet so he's still on the floor. Have browsed Ikea website but either too big or too babyish.