I wouldn't worry that much about the new KDE (3.4), does it have so many new features that you absolutely need it ???
I also used to want all the latest packages, but looking at the actual improvements (well, especially the improvements you really are going to use) I noticed that there wasn't that big of a difference between the different versions (I waited a long time for KDE 3.2, and when I got it, I didn't see why I had wanted it so badly all those months
About Eclipse. I'm an Eclipse user myself too. What I do is manually install the Java SDK from Sun in my user-directory and add the system variables (JAVA, JAVA_HOME, etc.) to my users .bash_rc file (this way only my user can use Java). Next, download Eclipse 3.02 from the Eclipse site, install (it's actually just unpacking) it in your home-directory. Next, create a launcher that launches Eclipse and specify on the launch command the location of the JVM to be used by Eclipse (I think it's the option '-vm').
Works great on my system.