For a tank this large, I would not use a hob
. Instead, I would use 2 canister filters. It will evenly filter the water without dead areas. What are the dimensions of the tank? I have a 150 Tall and use 2 Cascade canisters.
Also, when determining the size of filters to choose, you'll want the combined total filtration to be about 600 to 700 gph
. Do not rely on the manufacturers rating for how large of a tank that it can filter. They fib a little and tend to overestimate. If it were me, I would go with the XP2 and an XP3. Or maybe two XP3's. If it is a standard 150, I would go with two of the XP3's.
You could also use a sump. But I would definately stay away from hobs on a tank this size. If you're spending all of the money to setup the tank, I wouldn't want to have the filter showing. With a canister its all hidden under the tank.