Well the SX's would pretty much devestate the Cvx's in most areas. I'd say the SX's would probably take the 18 on spl wise on notes above 3xhz. The XXX would probably sound the best overall and hit the lowest, and would be very loud in the process, so I'd go with that...
You would be underpowering the XXX by far, if it is an 06 model. The SX's would also be underpowered as they are 1000 watts rms. I own two 12" sx's and I'm COMPLETELY satisfied... yet I'm running them on a KX2500.1 and that measly 1700 isnt going to touch them. An older XXX would be about what you're looking for... but good luck finding one.