Hello Mig...
If you're a poor water changer, then you can't have too much filtration. If on the other hand, you're a great water changer and change most of the tank water every few days, then you don't need much.
If you change a lot of tank water and do it frequently, then a cheap dual sponge filter or two is plenty. The filter does a poor job of filtering the water. It takes in toxic tank water and replaces it with water that's a bit less toxic. Filters don't do near the job a large water change can.
So, change out a lot of tank water every few days and save a ton on a filtration system.
B