Note: If you want to use their online offer, then you need the Java browser plugin because they use applets, ...
Yup. I figured that out during work today. That's the one I want.
Then try the Sun JDK (see previous posts).
Or try this (fairly recent) version of OpenJDK that I have repackaged from Fedora to Centos 5, it contains the browser plugin (i386 much less tested than x86_64): http://www.argeo.org/linux/argeo-el/5/plus/i386/
You would need: java-1.6.0-openjdk java-1.6.0-openjdk-plugin (WARNING: it replaces the stock Centos openjdk)
With the x86_64 version, I could open the applet of the online application you are referring to.