I have pychess but it seems to load the CPU excessively, even without the background evaluation tab.
I used to use xboard but by now the UI feels somewhat outdated.
I'm looking for good FICS integration rather than engines or analysis tools.
A bit late, but you may want to try Raptor
You won't have a ppa but they provide .deb installers for 32 and 64 bit Ubuntu systems. Has a very nice and customizable interface and is regularly updated (has its own autoupdater which you can turn off if you want, of course) Another option would be Eboard. Last but not least, you can try Jin but you will need to install Oracle Java to solve an annoying sound problem with openjdk.
It is possible to play chess on FICS using SCID. It can be installed in the usual way: