The concept is out-of-the-ordinary (which I personally love), so there will not be much reference material for you. But with a project like this, the best thing to do is to make your own reference material. No matter what your drawing ability is, I would first put a pencil to paper and start sketching. Be patient with yourself: this can sometimes be the most frustrating and time consuming part of a project because you are actually creating a visualization of what you see in your head. Analyze the characters with whom you would like to share an appearance, and figure out what it is about them that you like and want to replicate or emulate. Then work those elements into your sketch. The resulting rendering will be your reference material, and will make the creation of your costume much easier because you will have something against which you can check your work.
The other option is to commission an artist (usually $50-$100 depending on what medium they are using, how many colors they use, how long it takes, etc.). You would still have to analyze those other characters and give the artist a really detailed description of what you are thinking, but what you receive may be much more helpful as a visual aid (if your drawing skills are anything like mine, haha).
So yes, definitely possible to build such a thing, but you gotta accept it as your baby, since you won't be recreating the work of someone else.
