Trip was good - but far too busy. I didn't get to meet up with anyone in SA, though I did meet up with our partner Esra in Namibia, which was great. Wherabouts in South Africa are you?
If our pi content looks like the kind of thing you want to cache, then RACHEL-Pi should be just about the easiest way to get everything up and running.
One word of warning -- the Pi uses SD card storage, which doesn't have as long a life as a hard drive. So for trying things out on a small scale, it's great, but it won't stand up to heavier long-term use. For that we recommend the RACHEL-Plus which is much more rugged and has a bit more content.