So,
Here are you options with different prices:
The biggest upgrade would be to put a Bubble Blaster 3000S (select the correct adapter) (We are currently out of stock)
http://www.coralvue.com/reef-octopus-bubble-blaster-3000-skimmer-pump
You can also, put a Sicce 1000 pump (select the correct adapter)
http://www.coralvue.com/sicce-psk1000-skimmer-pump
Regards,
Carlos
CoralVue