Everyone will have a preference but I wouldn't go crazy with a wavemaker or something that pushes 1500 gph you know. I have a common green severum in a 125 with two tidal 110s and fx4 and it swims with no issues in the tank. It's housed with a few geos, no problems.
Not all plecos require high flow. Not good with scientific names at all, but species such as whiptail catfish may require high flow due to body being sleek for it then you have for an example a bristlenoses that will do fine in calmer waters.
Have you considered switching the corydoras for loaches. Species like the
yo-yo loach really clean the substrate and play with each other. Also tetras really love having huge schools. You might want to add to the group you have.