Edit & Extend PNG of Podcast Hosts for Poster/Billboard Use

I have a PNG image of Hilary and Michael Whitehall (as seen in The Wittering Whitehalls podcast artwork). In the current version, their shoulders are cut off at the sides, as it was originally designed for a square podcast cover.

I need a skilled graphic designer or photo editor to:
- Extend the image by reconstructing or completing the cropped shoulders, so it forms a clean, natural horizontal finish.
- Ensure the bottom edge is flat, so the PNG can be seamlessly used on wider formats such as posters, banners, and billboards.
- Match the existing style, lighting, and proportions so the extension looks natural and professional.

Deliverables:
- A high-resolution, layered PNG (or PSD if applicable)
- Completed image with flat bottom edge and shoulders fully visible
- Transparent background maintained

Ideal Candidate:
- Strong experience with Photoshop or equivalent
- Proven work on image retouching, photo manipulation, or creative extensions
- Ability to match photographic detail and lighting

Please include any relevant samples of similar edits you’ve done.