Image alteration

I'm looking to take several images (three in total - Image 1, image 2 and image 3) and to layer them into 8 different shades of grey.

I have attached an example of a finished product, but with only a few layers. I'm looking for 8 layers (many more than the example), including black and white and 6 grey shades. I have attached a chart showing all 8 shades available.

I have only attached 1 image I want converted as the site only allows 3 attachments however there are 2 more

Is this something you could do?

How long would it take?

Thanks

Peter