how big is the tank? A Wet Dry filter would be good or a simple overhead can be made using a power head, a bucket, a drill, some plumbing parts and of course filter media.
I would seriously recommend using a wet/dry. A lot of people are put off by them because they look hard to setup and confusing. But they're super easy and efficent. I have a wet/dry setup on my gachua tank. Before i did nitrates were about 50 between water changes. Now they're >20. MFK has lots of info on how to make one and they pretty cheap to make.