Looking at the costs of those modules, using an iPod touch or a cheap Android would seem to simplify things a lot, especially if you want accurate voice recognition, wi-fi capability (so that you can connect to the electronics that you want to switch on), etc.
Of course, if your goal is to learn/DIY electronics, then @Riva's recommended modules along with a standard Arduino Due would help you get started. The RFID reader listed there is actually reasonably easy to work with, so I suggest you give it a shot! If you read in the comments section on that Sparkfun page, the very first comment even provides sample code.