Please tell us more about your Java application. Does it have a database? What platform does it run on?
Also, it would be helpful to know what is appealing in SplendidCRM as compared to the Java-based ConcourseSuite http://www.concursive.com/
Your request does not sound hard, but it also does not sound like it can be done in a few minutes. The first question I would ask is if it would be faster to re-write the Java code in .NET rather then try to integrate.
Tells us more about your Linux requirement. Do you require SplendidCRM to run on Linux? It can be done, but that too can take some effort.