When running an amp at different ohm-ratings your basically dealing with the resistance for current to pass through the amp..

For example in your case running the amp at 1-ohm your amp would pull more power from the battery then at 4-ohms but also produce more heat at the same time...

I'm actually thinking of buying the same sub (also dual 2-ohm), i would say hook it up to a 2-channel amplifier [each voice coil to a separate channel] where your amp sees two separate 2-ohm loads, somewhere in the range of 200-300 watts RMS x 2 @ 2-ohms..

Good Luck