Texas Instrument has released a development kit amazingly cheap only $49. It includes a watch that has temperature and altitude/barometer sensors, and also a 3-axis accelerometer (like the Wii remote).
It also has a wireless link to other sensors like HRM, pedometer or USB-dongle. The bad thing is that the link is 868 or 915 or 433 MHz. It is not 2.4GHz ANT+ like the Suunto and Garmin equipment.
Anyway, there exists HR-belts with R-R measurement. The watch also has log functionality for several hours.
The display is a bit limited compared to the dot-matrix type of the Suunto watches, but since you can program it freely, you can get lots of info output with some creativity.
Included are a lot of open source sample programs.
If we cannot get what we want from the Suunto watches, this could be a candidate. It is a lot cheaper than a T6C for sure. And freely programmable.
http://www.ti-estore.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=eZ430-Chronos-433
