Ok, well there are a range of different filters.... we keep alot of Africans, we run Aqua One very big canisters on some of our tanks, and Eheim also...
Depends on how much you want to pay for filtration? I would definately run two canisters tho, more filtration and the bonus with that is.. if one needs something doing to it, you will always have the other one as backup... we have two huge canisters running on our big African set up in lounge, and they get rostered cleans.
There are cheaper range filters out there, Jebo etc, (of which we have owned and have parted with most)... Aqua One, have found they do a great job. Fluval, I don't think much of their filtration powerwise personally... and Eheim, ours crank it.