A big fan of VM's myself, how about getting a VM (Used to use VMWare, but VirtualBox fan these days) of your favourite distro up and running, install all of the necessary software, take a "snapshot" of it (shut down is safer, but you can "snapshot" a running VM).  Do your wallet transactions inside the VM after booting it up, transfer the file to cd/usb stick/whatever..., shut down the VM reverting to snapshot.  Then you won't be needing to install the software every time, but you still get the benefit of having a system which doesn't actually contain your wallet.  If you are extremely paranoid, download the software installs separately and install them in the VM while not connected to the web.