The Pi 3 follows on from the Pi 2, increasing processor speed to 1.2GHz and adding bluetooth and wifi support onboard, whilst keeps the same form factor.
DC-DC converters on the dual USB joystick board for the C64.
Raspberry Pi B+ I used to run Spectrum emulators.
Commodore 64 Pi is available from my Etsy store. There are lots of options available, and different combinations, let me know what you want and I will see what I can do.