Downloading en mass

Hi I’m looking for a way to download all of the available plugins/themes? I am going to be working offline for quite a while (over 6 months) with only brief periods of time connected to the internet to mostly communicate via email. I won’t have a large bandwidth quota or a fast/stable connection and will be unable to download plugins and themes.

I will still be developing sites and plugins for my clients, and would like to be able to use the plugins and themes as a reference instead of relying on the internet like I usually do.