I need ad designs for our advertising truck

You will need to make digital ad designs with one going on the side screen (dimensions of 768 pixels wide by 384 pixels height) and one ad for the rear screen ( dimensions of 512 pixels wide by 384 pixels high). In most cases the ad will be the same for both but just playing with the ratios. We are looking for someone who will be able to produce many ads going forward, as this is not a one time deal but a working partnership.