I'm puting my vote in for a Fluval 204 or maybe 304. Not sure if the 304 would be to much current for what your setting up, but I tend to like the current myself.
I think you were probably looking at the Fluval 2 or Fluval 4 filters which are internal filters. The Fluval 204 is an external cannister. This all being said when your looking at filters the 04 Fluvals are being replaced by the 05 series now, but they are still the same filter.
When I was looking at canister filters I was guided away from the Fluval 204 because it is an internal filter and I have a planted tank
I think you were probably looking at the Fluval 2 or Fluval 4 filters which are internal filters. The Fluval 204 is an external cannister. This all being said when your looking at filters the 04 Fluvals are being replaced by the 05 series now, but they are still the same filter.