I've a small situation here. Say, I've to gather a huge amount of information for setting up some service for the member; this may take some 40-45 screens, each having 40 to 60 form elements. As you can imagine, the user may go back forth while using the system and thus may require multiple DB trips. Such information are gathered, stored, and then may have pages which presents a summary view of the information.

Thus, as you can say this system has the following architectural requirements:
1. High Concurrency
2. Large sessions
3. Large number of Database transactions
4. Sophisticated user interaction to collect data

Will I like to use portlet as a MVC controller and deploy this portlet on a Portal?

I would like to get a view of the community and technical architects; what is their suggestion and recommendations?