JTA transaction manager for Spring + JPA System running on tc-server

We are setting up a new project with JPA 2.0 based on Hibernate 3.5.1 and Spring 3.0.5. 
As application server we are using tc-server 6.0 which is a flavor tomcat 6.0.
We would lilke to integrate an open source (LGPL or similar licensing) JTA transaction manager in to the system.

I am finding it hard to figure out a suitable JTA transaction manager.
1. JOTM looks like it has no support since Spring 3.
2. Atomikos  have only version 3.6.4 in the maven repository.
It looks like it has some problem and I cannot find any older/newer version (I am not sure about its licensing as well…)  
Can anyone recommend JTA transaction manager for me?
Does XA is included within such packages or do I need XA support as well?