My best bet would be on a fresh install with the NetInstall and the option of
encrypted LVM; this would make 3 partitions something like this:
/dev/sda1 = /boot
/dev/sda2 = extended
/dev/sda5 = logical encrypted with cryptsetup and partitioned with LVM
And sda5 has swap and root under the encryption.
I suppose u can resize the lvm partitions and managed them the way you want
and afterwards updating the /etc/fstab file.
If you can, I strongly recommend you to play in a virtual environment (ex.
VirtualBox) before trying on the real box.
Also, keep in mind that if you manage to successfully encrypt all the
partitions you want, in the current configuration, you'll have to enter the
password for each of them at boot.
