I want to branch out into Java coding. What's the IDE of choice? What's the flavour of Java that's at the more functional end of the functional vs. easy to learn gradient?

Ta.

NetBeans is the most Windows-friendly IDE, but Eclipse has more plug-in support. Try both and see which one you prefer. I'd also recommend looking at Aptana Studio, which is based on Eclipse but is more betterer. It's targeted at web development, but works for Java too.

Java only comes in one flavour: Java. (It's not very good, especially compared to C#).

You can get pretty much any language running on the JVM: I'm a big fan of JRuby at the moment, and I'll probably have a look at Clojure at some point.

You might find NetBeans better for odd language support, actually. Certainly for Ruby. Not that I approve of IDEs any more.

I was thinking J2EE vs J2SE... type thing... have things moved on? :)

I want to be able to programmatically draw vectors and text to the screen and make form-based apps too...