Second Allison's suggestion. I think JY mentioned somewhere to get this watch:
http://www.amazon.com/Casio-MRW200H-7EV-Sport-Resin-Watch/dp/B005JVP0FU/
I don't use the 7sage timer... I use an analog wrist watch and I don't cheat.. its just as good... probably better as your guide on test day will be your watch. Proctor instructions typically vary by a few seconds so it will not be much of an issue.