We got DSS a loft style bed that has a pull out bed underneath, but also pull out desk too. It has heaps of storage (the stairs are all small little cupboards)
I think we got it from furniture galore.... its brilliant and he loves it and is great for sleep overs.
We did look at the Kendall bed initially, but decided this would suit us beetr cos of the pull out bed...

ETA - DSS is 10, however we would have had him in it at a younger age, and her had bunk beds before that (they were mine when i was a kid )
HTH