Hi Guys

I need some guidance around how to develop the app I'm working on.

It's basically a backend system to manage photos and slideshows (eg arrange photos in albums, decide which ones to publish, update names and captions etc)

I would like to avoid giving the source code to clients but would like to keep the actual photos and thumbnails on the client's server.

I'm not sure what would be the best way to achieve this. In my mind the steps are:
a) client uploads a photo to MY site
photo is registered into my DB
c) the original photo is moved to client's server
d) thumbnails are generated and saved on client's server

then the public site:
e) install the public website on my client's server;
f) when a user is browsing the client's website, the script gets the list of images to show from my database, and gets them from the local server.

(hope I made myself clear)

basically the question is: what's the best way to give the client minimal/no access to the source code?