I would recommend looking into Noeprodigy's 600 gal build. You might scale it down a bit though. LOL Go with the Ultima 2000 and an FPI inline filter housing. The FRI uses filter socks and is easily changeable. It's a bit pricey, but worth it IMO. Of course, if you do some Google'ing, you might be able to find a cheaper option than the FPI brand.