how to identify which version of 8s I just bought

I just purchased a new devo 8s and I am looking to install new custom firmware. first off I want to find out how to identify which version i have, as I wanted to install the latest firmware (if 3.0 will work). if i am running 1.0a or 1.0b then what version do i install in the nightly builds. do I first start of with version 2.0.0 or do i start with the newest version.

thanks for the help in advance.

The latest v3.0 nightly build supports both older and newer versions of the 8s. The nighties are still in beta, so don't fly expensive models with it yet.

if for some reason i would require to roll it back to original is it possible to roll it back to factory firmware?