Hello CWB. The tank in the link has built in over flow system that has to be connected to either a wet/dry or
sump filtration. The tank is pre-drilled. It's really a matter of preference. By having it pre-drilled with the built in over flow allows you to push the tank up against the wall and you don't have to leave space for hang on back filters. Too you can have a much stronger type of filtration. The only draw back to this type of tank is having to crawl under the tank to do the plumbing.
Too, with the built in over flow you never get the film that can build on top of the water and too you never see a water line.
Ken