Website builder and designer needed:

I'm starting a non profit organization that is a pen pal service for incarcerated individuals. Right now, the ones available are difficult for incarcerated people to sign up for on their own, are very expensive, have romantic connections as the main reason for writing to an incarcerated person, and does not keep addresses private. Incarcerated folks deserve better than what is available right now. I am at the very very beginning of starting this service and I am looking for someone to build and design a website for this project. I need something to show potential donors/investors so they can see how it would work. 

Pay is about $500 per completed job (but is negotiable) and this work can be done remotely.