i seem to remember just replacing the pump with a mesh modded maxi-jet...ask daily driven 911, he's the one I did it for and he had both the modded maxi and the modded stock pump that i meshed, and i cant remember which was better...
but i think your better off just stripping out the lame filtration/skimmer they have back there and replacing with a good hob skimmer and a bag of carbon/gfo