I've found that the best combo seems to be to use both a canister AND a power filter AND a sponge filter.
I've got a 29 gallon over-stocked tetra tank in which I keep all my little neon and neon-like fish as well as pristellas and some varieties of bloodfin. Its got fifty some fish in it and thus needs a little more than a HOB in terms of biology per gallon flow so I splurged on an EFU-45 JBJ unit. They are noisy like a standpipe but do a great job.
I use a one liter intake pre-filter sponge on the EFU then rout its output up into the impeller of an Emperor 280. This lets me put the carbon/purigen/hypersorb/etc and final 50 micron filtration in the HOB and never have to handle the insides of my canister.
Its a lot of filtration capacity for a tank that's also planted, but it works great and is very predictable.
The bottom is one box laterite and a 24lbs bag of fluorite sand capped with black volcanic sand.
Makes a very happy tank and a very easy maintenance plan.
So that's my sponge filter, canister filter and HOB arrangement. I really advise it for its ease of use and general reliability. Its like an enormous version of the rear-wall filtration you find in bio-cubes with the added benefit of what each system brings to the table. If I ran a bigger tank with more fish I'd likely add the HOT 250 on the front end instead of the pre-filter sponge, but I really don't like having tanks I can't move on my own.
I could probably get away with a Fluval 106 and a Penguin 150 return...
but I like the beefy equipment. Never loose a fish to weak hardware.
I guess in the end the whole filtration question comes down to "what won't kill my fish, what will let me sleep at night, what is too much?"
A good one liter sponge is equivalent the entire under gravel system of a properly maintained 55g with under gravel... except easier to maintain and it doesn't bother plants.
About 1200ml of soft fired clay type media in a canister, or 2 liters of hard fired ceramic media does the same job but can take longer to establish. This because the sponge can grow cycle bacteria directly on the caught waste and canister media is designed for flow-pass. The difference between the soft and hard media is that the bacteria can sustain themselves on the calcium from the soft media.
Hard plastic media like bio-balls and pin-balls as well as cheato and other surfaces like the blue thing in Aqueon filters do work, but the ratio on them is so poor as to be pointless. I can replace two cubic yards of the best bio-balls with four liters of Hagen bio-max and a good protein skimmer.
By far your best fresh water option is plants.