The right subs would be the Kicker 48CWRT124 12" 4-Ohm Dual 500(Watts RMS) Voice Coil Design Subwoofer-Black, your listing,
eBay item number:134177017807 for $183.96. These subwoofers minimum air requirement is .55 cu ft, which will work in that enclosure, and the power has a range on their website of 350 -500w RMS in a sealed enclosure. I could then use your amp to get 800w RMS @ 1ohm, sending 400w to each subwoofer. These subwoofers will fit, just like the others and I would like to exchange them.