Additional Graphics for Existing Game App (IOS and Android)

We have an existing app in Apple and Google stores. We would want to add around 20 or so images (some images will just be cut into layers/pieces so there is probably be less than 8 unique illustrations needed...see attachment) that looks like the attached concept. The concept is basically, the images (requested) are square or rectangle shaped and placed against a black bg like the attached...all of it must work in Portrait mode. High quality images with the least amount of size (under 100kb is desirable). Image size should work for any aspect ratio because design is in the center, but be under 640x960 pixels. Would like light weight jpgs and pngs only when transparency is needed. We would the art to match the style characters and the background styles. We will provide app name, videos, art styles, examples, etc. to qualified bidders only. Images could also be borrowed from the Internet but must match the theme so some editing at a minimum is required. Must have an iPhone to use app version that we would want to add graphics to.