Hi, I am an expert level PHP developer, osCommerce is my tool of choice and I have developed over 50 eCommerce sites using it. I know every single line of it and can customize it to any level.
If I understand it right, what you need is a concept of attributes images, where you could assign images to product attributes and people could select attribute by selecting appropriate image. I have done that for a website which was selling school uniforms.
I am ready to start right away.