{My New House - Son's Bedroom}

I'm in two minds as to whether or not I put my son & daughter into the same bedroom in the new house or keep them separate. I'm lucky enough that my new house has three bedrooms, and as I'm short on storage, it might be useful to have the third bedroom as an office / dumping ground rather than utilise all bedrooms as actual bedrooms.
Anyway, my son has been talking about his new room and he's rather keen on a superhero bedroom. Which you probably could have guessed on the basis of his recent birthday party theme!
I've been doing some research and collecting my ideas over on Pinterest. I'm seriously addicted to this site!!
The carpets for the bedrooms are likely to be gray. I'm thinking that they are less likely to get stained by my messy toddlers!
My son's room is going to be big enough that it can take a color on the walls (whereas the littlest's room is rather small & dark and I think it will have to be white/cream). I quite like the idea of blue walls and then I'll bring in the superhero theme with some artwork and accessories. This means that the theme can be changed as he gets older. I also don't want a baby blue and want something a little more grown up... here are my thoughts at the moment:


I love this vinyl sticker from dinosaurdecals which I spotted on Etsy:
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I also rather like these superhero posters, again from Etsy - this time PosterEmpire:
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And isn't this personalised comic book Pow! name print brilliant?
By Wordplay Design at notonthehighstreet.com
We already own this poster which will be great in a superhero room!
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I've just done a quick search for superhero bedding, and found this fab duvet from Next:
Superman bed set
I have a toy box at the moment in my back porch area, and I'm thinking that this might look quite good in my son's bedroom if I painted it red or yellow to give the room another pop of color.
The toy box, currently painted turquoise
So, what do you think? Any other ideas for accessories for a superhero bedroom?