Graphic design for online magazine ad

We have a client that needs an ad for a digital magazine. (See the two samples provided) I will provide all the images, headline, subhead, and copy. I simply need someone to build the ad. I'll need the same add created for two different output sizes: 792 px (wide) by 1038 (tall) px and 460 px (wide) x 792 px (tall). Output is a PNG file type.