Web Developer required with MVC, MySQL and Vaadin Experience.

I am looking for an experienced developer to start development on a new product demonstration. At a high level the product is a dashboard that reports on data within a MySQL or Oracle database, the data is to be presented in various user select-able widgets depending on the data, for example pie charts, bar graphs or raw data. The application is going to be a large multi-user application so thought needs to be given data caching and sharing among the application instances. A few menuing system will need to be developed, down to field level security to individual users, including sub-sets of the data in the database, for example user x can only see transactions for currency or company y. The application is to be written in Java, using the Vaadin framework, I have an existing application that as a demo but it wasn't what I was looking for as it was adapted from another project so I'm after something being written from the group up. I am looking for someone who is self sufficient and who doesn't require detailed specifications, ideally I would like to be able to provide a high level requirement, such as "display the data from this table as a line graph, the data needs to be extracted using the following SQL" The application must have the "wow" factor, be usable on all devices and use responsive screens, hence using Vaadin as the framework. Ideally I am looking for someone who can also advise on best practices and current trends on web development technologies to help shape that product. Although the initial engagement might only last a couple of months, there is further work to develop the rest of the product.