Based on the volume of the box, I have decided on the JL10w6v2, which is a 10 inch model. It's recommended volume is exactly that of the box. It should sound as good or better than two JL10w1v2 subs under the back seats due to it taking 33% more power than both of the w1v2 subs combined.
I will say that the one you have linked looks mighty tempting since it fits the box volume perfectly when set up for 12 inch speakers.
Mark H