Definitely interested in doing this for you. It sounds like your research involves seeing who chooses what image, or how many people choose certain images.
The requirements are quite clear, let me see if I can break it down myself to make sure we're on the right page.
You want your staff to be able to login and create a keyword. Then upload 4 images to IMGUR (or some other server) and essentially assign those 4 images to that keyword.
Then you want other users to be able to browse through? view? the different categories and submit a vote for a particular image on each category.
Lastly, you want to turn that data into something usable. We can talk about different ways to output the data, perhaps even graph it if you want later.
I'm in the US, near Chicago. If selected can be available over the phone, Skype, email, etc.
I plan on using a framework like Laravel to get this done for you efficiently and rapidly, while still keeping up with modern best practices and security.
Let me know if you've any questions.
DISCLAIMER: I plan on using something like Twitter Bootstrap to make it look somewhat 'pretty' and put together a functional visual design. I am not a designer, artist, or anything like that. I'm an engineer that will give you a usable product based on your requirements. It's not going to come with high end design/graphic work. If you want me to elaborate on this, just ask. :)