Post-Processing service

i would like to provide a service on my homepage for photographers to send me shootings in order to let me post-process the photos for them. it’s important that the interface is very easy and simple, and i’d like to integrate paypal…

does anyone know a good plugin for this?
does anyone write plugins, and can do this for me?
or maybe i just need to mix 2-3 plugins to do this?

here is a mind map on how i imagine this:
https://marcgerard.lu/wp-content/uploads/2012/03/postprocessingservice.jpeg

here’s the portfolio:
https://www.marcgerard.lu

i’m noobish, please help ??
i pay with money, or with post-rocessing ??
thx!
Marc Gerard