Neji

Dspeech. It takes a voice synthesizer, and can output it as a music file. (Wav...)

You'll need to find some voice synthesizers, though. They also are pretty costly, if you're going legit. (I recommend checking out AT&T's synthesizer, they even give you a demo of the voices you can get. http://www.research.att.com/~ttsweb/tts/demo.php)