here are some guidelines as well:
must be SPDT or DPDT
must be a Form C relay
3Volt coil voltage
Switching voltage should be close to what you are switching but most common would be 110/125 volts.
i BELIEVE but im not sure, that you would want a non latching relay. a latching relay will stay in the last state it was on and are generally dual coil. perhaps someone else can comment whether it needs to be a latching relay and if it needs to be single or dual coil.
coil current should be as low as possible in this situation as there isnt going to be much current switching it.
a relay like this should work:http://search.digikey.com/ca/en/products/T...322-5-ND/649886