Pulse Sensor for Arduino (5Volts)

Is it ok to use arduino decimila instead of arduino uno to connect this pulse sensor?

Here is the link of the pulse sensor http://www.makershed.com/Pulse_Sensor_for_Arduino_5_Volt_p/mkre1.htm

Is it possible to connect a relay circuit in a arduino decimila? were everytime it pulses it triggers the relay.

Is it ok to use arduino decimila instead of arduino uno to connect this pulse sensor?

Yes, however the code need some small changes ...

Is it possible to connect a relay circuit in a arduino decimila? were everytime it pulses it triggers the relay.

Yes, but the relay should not draw too much current, better switch the relay by means of a power transistor..

Another question sir. About the pulse kit. Is it ok if I don't use any arduino, Can I connect the relay after the pulse kit?