It sounds like you’re currently on an IBM platform so why not use IBM to do the conversion? They bought the Rational Software about 3 years ago, and now have a system of Rational pieces that stand on top of the Eclipse editor, which includes the traditional Rational suite of ClearCase, ClearQuest, etc..
The one you would be interested in is the “Rational Architect” that includes “EGL” (Enterprise Generation Language), which automatically converts COBOL to Java.
This is an appealing choice because there are many automatic code generators for Java (after the conversion takes place, and you are a new Java developer) that can create code from Use Case diagrams for EJB (beans), and actually hook together the source code, Use Case Diagrams, Requirements and Incident reports for totally integrated project management. Do not have experience how well this works as my company is just starting down this road – but certainly looks like a great choice so far.
I have been using Eclipse with Rational Clearcase and ClearQuest for several years, but so far I have had to download and put in the add-on plugs myself. This new system is already totally loaded and ready to go.