Filter for 5 gal tank w/one betta

[onebettanewbie]

Hello! I've have my 5.5 gal tank set up for a month. It has one betta in it with live plants (anubia, wisteria & java fern) and a stealth heater. The tank is fully cycled thanks to a large borrowed canister filter which I need to return at some point.

When I started, I had a Penguin bio-wheel HOB filter on it but it is a little too deep for the Versa cover and it felt unstable. I replaced it with a Tetra Whisper 10 filter but the current prevents my betta from swimming anywhere near it. I rigged up a sponge cover over the outtake to soften the current but I read that isn't healthy because it cuts down on the aeration.

Can someone recommend a good set up for me? I'd like a filter that does an excellent job filtering the water, provides sufficient aeration and is quiet. Is there one that can do that and also be adjusted so my betta can use the full tank? I would consider a internal filter with an air pump but my borrowed canister filter came with a Rena Air 100 pump and I can't stand the vibration.

Thank you very much for your advice! I'd love to get this settled so I can stop obsessing about it and return the borrowed canister.