[noodle]

an arduino, an arduino book if necessary, and the rest on whatever parts you want to buy to build something.

[elpuri]

I've done quite a lot of uC and FPGA stuff already, but thanks for the suggestion.

Assembling from a kit and developing own firmware for something like this http://monome.org/devices might be fun. Even if not used as a MIDI controller it could be a nice toy (visual effects with human input).