my opinion is to jsut buy one amp first. See how the subs run getting 250 a piece. If you don't need more then great less money. Then if you want more get another identical amp and run one to each sub so youll have 500 to both subs. Keep im mind the more power you run to the subs the more of a strain your putting on your electrical system.

I would not reccomend running the left channel to a voice coil and the right to the other voice coil. If thats what was suggested in the middle. (wasn't sure). If there is any channel imbalance at all the sub is going to be fighting itslef and not sound good or even blow.

Make sure if the subs are 4 ohm dual voice coils. If its different it will affect your choices. The options will be a bit different.