Haven't tried these yet but they're HTML5 so no installation. School computer support maybe be a little difficult. One is pay for and the other is free.
Scratch an itch that you currently have with a program that you're currently using. Whether a new feature or a fix to a nagging bug it will be more enjoyable working on something that you already use and care about than a random project that you don't know very well. Hopefully once you start you'll contribute to a few different projects.
The 5 port SATA backplanes were the hardest part to find when I built these. You can get them through http://www.chyangfun.com/ which is who Backblaze gets them through and we did too. They are hard to get ahold of sometimes so that's why I was looking around and found some shady companies selling them. Protocase mentioned above sells these which would probably be the easiest company to get these through.
Other than this, the other parts are pretty standard and are easy to find with some simple searching.
FYI: Protocase (http://www.protocase.com/), the company that will build you the Backblaze case, sent me an email yesterday announcing that they are now selling completed Backblase storage pods without the hard drives for $5395.00. I'm not sure if this is the new design or not but I've set up 3 of these and finding some of the parts (SATA back planes) took weeks of searching and shady dealings.
Guacamole http://guac-dev.org/
ThinVNC http://www.cybelesoft.com/thinvnc/
Andrew