Designing Custom Theme/redesign for Ning 3.0 Network

We have created a community website based on Ning 3.0 Platform. This platform has its own standard theme which is very simple and primitive. We want to redesign our ning 3.0 network with custom theme, css and javascript so as to make our community website look apart. Freelancer need to have knowledge about ning 3 architecture, modules and api's which will help in creation of good layout. Basically we want to add modern look and feel to our community. Delivery should be quick. Thanks!