Filter For A 15 Gallon

#1
Hello everyone. I'm on a posting rampage (at least to my standards) and I figured I'd ask you all one more question while I was at it. I am in the process of building a 15 gallon acrylic tank. I plan on finishing it within the week and I'm not quite sure how I should filter it. I have always used Aquaclears in the past but this one is going to be in a tight space so that isn't an option. Any ideas?