App in Google App Engine

What I need or require: I'm looking for a social website application that will be run on Google App Engine. What I already have versus what the provider will deliver: I have a design created, will be modified as needed by designer. Other context/requirements that providers will need to know: A custom CMS application compatible with Google App Engine, with emphases on user driven content and interaction. Specific expertise/background that I am seeking: Google App Engine experience with either Java or Python. Use of CDNs. Timeframe for delivery: 2 months