Resize 600 Images

I have 600 product images that need resizing to be 1:1 ratio.
Most will be straightforward but some will require backgrounds extending.
Photoshop AI tools are completely capable of extending the backgrounds and produce acceptable results.

I don't want this job done completely by AI, this will have too many reversions, all images must be checked.

Project will not start until 9am Friday 9 August UK time.

Please provide a price and timescale.