Well I finally bit the bullet and chose the wall decals from the myriad of options on Amazon, Ebay and Etsy. I ended up buying from Etsy as the options were the most flexible and also the cheapest. Rather than giving you one sheet with the decal printed on, it comes in separate pieces so you can be a bit more creative with the way you apply it.
I think its going to be a bit of a mission but I am dying to get cracking with it. Unfortunately, we have decided that the wall needs a lick of 'feature' colour to set the design off properly and I have to wait 2 weeks for the paint to cure before applying the decals or they might not stick properly. Lovely Husband is up there right now painting the wall so I will just have to be patient. (pics to follow)
We also decided to return the changing dresser as we have been offered a second hand oak chest of drawers which is going to save us money and also be better quality and more individual. The only problem with this is its at the other end of the country currently so it's going to take some organising to get that up here. Still, I am very grateful to Fabulous Sister for offering it to us (and to Mothercare who allowed us to return the changer even though 28 days had passed since delivery.) and really love the idea of our little one owning something that her cousin has used every day for 11 years.