.....I can recommend Voice Attack, it's already in use with the likes of SC and ED. It works like a dream, and can be setup (almost) in your sleep. I setup some basic commands in SH5 i.e. Dive, Surface etc, no problems at all. You can also add voice (STT) scripts and pretty much make it say what you want. Fantastic product, you can download a demo and the cost is (cheap as chips) £5 or $8. I have no link to VA, just a really happy customer.
http://www.voiceattack.com/