Any designer can help you with this. Kirsty and I both use Octavio to create a mock-up box and our listing images, but you can also reach out to contractors on Upwork or a designer on 99designs. (and yes, we did discuss this in las vegas, great memory!)
And yes, in your brief, consider what you want your main image to project – this is a great opportunity to inject stand-out color, and promote your BRAND and BENEFITS or important features over and above competitors. Consider your top 3 objectives and share these with your designer and also show them a mock of page one so they can see understand what is required to standout on page one.