Choosing a PISO register

I need to find a Parallel input Serial output (PISO) shift register for my build. The input will basically only be a short from 5v, running through a diode and a resistor. I want to use a shift register to save pins on the arduino.

Any suggestions?

The chip used in the shiftIn() tutorial is a CD4021BE.

http://www.arduino.cc/en/Tutorial/ShiftIn