Use whichever you like; what matters more is how strong the filter is, not whether you use a venturi or spray bar. One caveat though: venturis reduce the flow of water (by making the filter motor work harder) and so reduce the amount of filtration. This is usually explained on filters that have optional air-inlet systems, such as internal canisters. So if you want maximum filtration, use a simple spray bar or spout instead of a venturi.
The other thing people neglect is water movement at the bottom of the tank. In a tank with adequate water movement at the bottom of the tank, all the poop and detritus should collect in one corner where the current is weakest. If stuff collects all over the substrate, then you don't have enough water movement. Movement of water is what pulls oxygen to the lower level, and this is very important for catfish, especially species that come from high oxygen environments (e.g. Hypancistrus zebra and Otocinclus spp.). Fiddling about with water movement at the top of the tank without considering what's going on lower down the water column can be a dangerous oversight.
Cheers, Neale