Poster Editing for Website

I need someone who can edit a number of photos - 150 to begin with but this project would be ongoing up to 500 plus photos.
1. A white mount and a black picture frame needs to be placed on top of each photo just overlapping the edge of the photo. A number of the photos have magnets (black square and white round) on edges and corners - if not too obtrusive these can stay but would also be interested to know if these can be edited out.
2. I intend to purchase 5 blank interior wall shots from Shutterstock - once the above has been completed I need the framed images to be superimposed onto these Shutterstock images - varying the wall image.
Both images will be used on my website where we sell vintage and contemporary movie posters.
Not all posters are the same size but is it possible for posters that are physically the same size/category to be edited as the same size i.e. all Australian Daybillls to look the same size when featured on the website. Same for other sizes Quads, One Sheets etc.
The three attachments are for an Australian Daybill (showing magnets) a typical One Sheet (edited with mount and frame) and a typical quad.
TIA
Paul