9 Movie Posters On 1 A3 and A2 Poster

I am looking to get all 9 of the Star Wars movie posters onto to one poster. The posters will need to be 3 in a row (1 Trilogy per line). I would also like a white gap between each poster and a white boarder. I have attached an image of how I am currently making these (individual prints and mounting).

I would ideally like to be able to print A3 and A2 size. Is this something you could do?

Thank you

Matt