Here at Diabloskinz it's possible for us to make a custom skin or case based on any images you provide.
We have made a case creator app on our facebook page, simple choose the device you want, add a picture and text and check out.
Here is a link to the Case Creator
However, if you are looking for a custom skin then you will need to contact us via the "submit a question" and tell us what you are looking for and provide us with some images.
We can only currently provide custom requests on current devices supported on the website