CD Rom/DVD drive in head press eyeball to open drive. All necessary input ports in the base. Hard drive area in the tree stump. The start button could be the other eyeball or possibly a toe. In order not to create undo stress on the case making the Statue of David himself hallow.
Another option would be to have everything in the base and keep David purely for decoration. Having the buttons as David's toes. Keeping all connections in the back.
You could also have built in speakers in the back of the knees or buttocks.