Two SunSun 404B filters will get you started at about $90 each. They hold a ton of media and have ok flow rate. You can easily add a third later on, if you feel the need to. They also have built in UV, so that's a plus. You will have to buy media since they come with very little, if any, depending on the kit you buy but the media can be found cheap on Amazon/EBay as well.