orion, viper, cliff designs or earthquake

okay i posted the topic 4 12's vs 2 15's and my boy decided to go with 4 audiobahn  1200q. He also decided that the jbl1200.1 amp aint powerfull enough so he is looking to choose between the earthquake dh2 5000 watt, viper d2500.1, orion 2500d, and finally the cliff designs cdx20a amp.b im gonna wire all his subs down to an 2 ohm load and im building the sealed enclosure right now for his subs. Now the question is which amp will give him the most spl. Oh he listens to mostly rap.

earthquake....3000 at 2 ohms........viper.......2500 at 2 ohms..........cliff designs cdx20a 4000 at 2 ohms...........orion 2500 at 2 ohms............................which amp is the best one