We have developed web order entry system for different business units
WITHIN our company using a third party software called "Versata"
(http://www.versata.com)
This was written in java environment using java/jsp/tomcat and versata
There are currently about 300 users of these application.
Recently our management decided to get rid of versata and re-write
these applications(22 applications) using either .NET or JSP
technology.
I would like to know  what will be the best suit for us in this type
of situation.
Ours is a Windows environment, so portability is definitely not a
question.

The main concern for me here is the connection from these applications
to our DB2/AS400 machine.
Currently we are using "IBM toolbox for java(jt400.jar)" to talk to
AS400 from java application.
From a .NET environment IBM has .NET driver but not specifically for
DB2 running on AS400
(http://www7b.software.ibm.com/dmdd/downloads/dotnetbeta/)

I know there are lots of knowledge-base out there giving the
comparison between these technologies when you do a google search.
Please note that , that is not what I am looking for.

What I am expecting is a clear comparison with explanation about these
2 technologies keeping AS400 in mind.
Somebody knowledgeable in both .NET & JSP and has worked in IBM-AS400
environment will be a perfect fit to provide me a solution.
Thank you..