ARCH linux is a very simple distro.
Arch Linux
It would fly with a 2 ghz processor 2 gig ram and something like xfce for a desktop enviroment.
pacman makes system updates fast and painless , well 99% painless
Simple does not equal easy so there would be a bit of a learning curve, but you would be able to laugh at the setup of an AZBOX HD after you configure your ARCH box.
PC-BSD is a very worthy project but the method of package management is overly complicated. I understand what the goal is but do not agree with the path that they have taken.
do yourself a favor and learn linux, not just a commercial distro. SUSE is a very complex distro.