Don't buy a speech recognition product until you have checked out recent product reviews. The technology is changing rapidly. Speech Recognition is not right for every one. Some people get voice problems from it, or don't have the commitment to really get it working well. Rest your hands on a soft pillow while using speech recognition software.
Some people get voice problems while using speech recognition.
You might even want to consider seeing a voice trainer or speech therapist. Before you start a SR session, put a glass of room-temperature water on the desk. Drink often during the session. Gradually increase the length of SR sessions. Soreness will quickly follow if you don't.