If you have two 1" drains from your tank they should be able to handle almost 800 gph each (could be pretty noisy depending on your overflow).
An Ocean Runner 6500 is rated 1625 gph at 0' .
http://www.customaquatic.com/customa...mid=WP-AM70003
You can find them locally as well.
I used one on my 120g tank with two 1' overflows.
You can always throttle back a pump with a valve on the output, better to have some extra gph's in case you want to feed other equipment down the road.
I'm not sure of the Mag drive model stats. I've haven't used them but a lot of people do.