I have a lot of Cybot and Tom gear, always planned to replace the inards with a Raspberry Pi. This will be a good learning exercise.
Electronics
Raspberry Pi
Let's say that I have quite a lot of theoretical experience with Raspberry Pi as I've read a lot about it and have tried one or two of the projects. I found them to be reasonably challenging, just difficult enough to keep you interested. But once done, easily done again.