Portal (Portlet) or AJAX ?

I am going to develop a web application but not sure what development framework is better.
Nowadays, there are many frameworks for developing web application. For examples: JSF, JSP/Servlet, Java Portal (Portlet) framework, Springframework, Struts, Webworks, and also AJAX, etc. Too many taht I can't list or really know about them.

My first choice is Portal(portlet) + Ajax. For using Java as the development language, which portal is better? I prefer JBoss Portal, the framework is more structure and easy to use. The Liferay Portal has many well developped portlets for use.

Anyway, both of them I give up but customized the Apache Pluto-2.0. It is in the development statge. I want to get more suggestions on a Java Portal Server. Let's say, functions, arcvhitectures, etc.