I'm not sure how big you're planning on making this site - it appears to be pretty small, however you are using at least 2 servers. So...

Consider, when you upload the images, writing the image location/description/size/other metadata to a database.

That way you don't have to connect to the other server at all. And it means you can upload your images to any server, just as long as you specify which server it is in your database entry.

It'll also be quicker to read a few rows from a database than to make an SSH or FTP connection and do a directory lookup.

But this may be more complicated than you're after.