The only other two that I know of are the BodyMedia Fit and WildDivine Iom. Neither of these are likely what your looking for though; the BodyMedia Fit is really just for calorie tracking and the Iom is really just for meditation/bio-feedback. (Although there still both pretty cool)
I had the chance to see the Q Sensor in person at the Boston Meetup and was quite impressed, but I think I’ll wait a little bit longer for the Basis and save about $1700.
Might be worth exploring these people: Wild Divine - as mentioned above by Ryan, but I think you can do more with it than it might seem at first sight.
It all looks a bit new-agey when you get there but I’ve ordered from them in the past, and have their (GSR) galvanic skin response apparatus which didn’t cost a fortune. I was also able to download some software from them that creates a realtime GSR graph on my Mac.
It’s all packaged up as a kind of biofeedback application, but you can (or could) choose to ignore that and just use the hardware and the charting package.
Sorry this is slightly vague, but it was a while ago. It’s probably not incredibly accurate but a psychologist friend was pretty impressed at what you get for the price.