I think this comes down to your choice. Personally, I like sponge filters since they are fry-safe, cheap (you can buy two of some sponge filters plus an air pump for the Fluval's price) and some are stackable - they can be grouped/scaled up if you move them to a larger tank. Admittedly, I've never found a really, really, quiet air pump, so that is an issue if you don't like a background "hum". Sponge filters aren't pretty, but they do work well. I'm using stacked sponge filters in my 125 and the water quality is great! Do another search for "sponge filters" on Amazon, you'll even see some triangular corner ones and some priced at $4-$6.
I've never used the Fluval and it looks like it would work, but it's also rated for "up to" 15 gallons, so might be undersize for you. I wonder how large the included foam pad is? I bet you'd have more actual filter media surface using something like the HydroSponge II.
I've never used the Fluval and it looks like it would work, but it's also rated for "up to" 15 gallons, so might be undersize for you. I wonder how large the included foam pad is? I bet you'd have more actual filter media surface using something like the HydroSponge II.