Graphic design for a retail display unit

We have a very time sensitive, urgent project underway and we need some one to do the artwork for a retail display unit that will hold gift cards. We have already completed the design except for one part of the unit that is a flat, rectangular area of 427mm x 540mm section. We want to fill that space with a cartoon or pictorial style representation of how the gift cards work. We have the copy and the concept in place, we just need a graphic that helps illustrate the concepts that we have in mind. In other words, the graphic will be diagram how the cards work in a friendly, green theme. Custom illustration would be great but we are in a hurry so we are open to licensing stock images if needed. In any event, we are looking for someone with a creative flair who can start immediately and work quickly. The design can be done in AI, Photoshop or anything that is print friendly. Keep in mind that this will be printed onto a pretty large area so it will have be very high resolution, print quality graphics. Please provide examples of previous work. We will provide the person that we award the project to with with a 3D image of the display so you know what you are working with. We will also provide background on the company and additional details so that you have a good understanding of the look and message that the graphic should convey. We'd prefer to work with someone in North America so that we can more easily collaborate and not have the time difference issues, but we are not ruling anything out.