I would avoid Illustrator for anything includingthat includes photos. Illustrator tends to get slow when loaded with too much raster assets (photos) since AI is generally built for vector artwork.
Between the two, Photoshop might be your first choice here since you seem to use alota lot of photos. Be aware PSD files tend to grow in size rapidly when using many photos in print resolution, so working with a 1-2gb PSD is not ideal, in which case you should be looking at a mix between InDesign and Photoshop.
What this means is process the photos in PS and design the poster and layout the text info in ID, which works better with fonts and allows more control over formatting and overall templating, etc.