The EP2500 will NOT do 2000w @ 4ohms.... Its been measured, it will do 1600w - maybe 1700w bridged, but for a sealed sub you will need to add EQ to boost response at the lower end. When you do that it will eat up even more amp power that the EP doesn't have enough of to begin with...
Real world testing will tell you more then just posting numbers, I have done that with both the EP2500 and the QSC 2502 and both ran into the same problem on the Mal-X's, just not enough power. They did get pretty loud, but not loud enough for what I needed in my situation. The Mal-X's can handle some serious wattage, I'm running each of my 3 Mal-X's with Crest 8002's now that will put out 4000w bridged, I no longer have the problems I had before with the smaller amps. I am not giving them the full power of those amps, but I have plenty to spare if I upgrade to the new upcoming 2009 18" LMS's down the road.
Ported may be a different story, as well as size of room and how much SPL you are looking to get out of these drivers.... so YMMV based on execution.