Yes, I would recommend downloading and using all of the PoodLL plugins. The only one I think about being optional is the PoodLL Online (assignment_poodllonline) as it is for the old Assignment 2.2 type, which I no longer use.
Your first link you have listed above downloads directly from Justin's site and if you get the Kaboodle, it will include all you need to get going.The second link is also ok, just have to download the different parts, one at a time. The main add-on of the bunch that all the other parts depend on is the filter. Their installation depends on the filter being installed, too.
If your site folder permissions are set right and your site is registered with Moodle, an admin can actually do all the installs right in Moodle 2.5.x, by going to Administration > Site Administration > Plugins > Install add-ons then click on Install add-ons from the Moodle plugins directory.