Nice start. The SunSun filter should be plenty. I have an Aquatop Cf-400 (which is just a SunSun hw-303) on my 29g and have had no problem with aeration. I have my spray bar a couple inches below the surface and angled up slightly, causing a slight ripple. That's mainly so I can see if it's running since I can't hear it.
If you want a quick way to hide the cords, you can use the background material sold at most pet shops. It can be applied to the outside back of the glass with an adhesive, or even taped in place. And it can be done with the tank near the wall with a little work. I managed mine with the tank about 5 inches from the wall, and I think the black background made the plant and fish colors show much better.