Web Application using Node in View and Rest API for CRUD operations

We are developing new E-Commerce web application from scratch . After some primary investigation , we wish to develop some prototype with

   Node.js in view Layer and  
   REST api for performing bullk CRUD operations and  
   node.js asynchronous event-driven model for very light I/O

Does it have any performance improvement over our original development platform JSF-JBOSS-hibernate ? Especially in response time and through-put ? No of concurrent users always > 1000.
[ Expecting arrange 1500 to 4500 ] . [ We need node.js just because Customer demands that ]

Am new to Node.js . So Does we can depend on socket.io mechanism for an enterprise wide data communication between client and server . ?

with regards,

Sijo Thomas