Yes I said the lower one and I also said that the Cascades are very powerful filters and in order to not flush your fish nor plants out of the tank, that's why I had said that model cause it will do the work without being too much (which you'd not want on a planted tank).
So if you wanna go with the 400 model on the top right above the outlet dial that WAYYY down as far as you can get it when you get the filter in then.
The internal will def be muchhhh less noise (regardless what model now) then the sponge filter I can tell you tat much. I have the 600 here and unless I push my ear to the side of the tank while the house is 110% quiet I don't hear nothing and even then only a lil humming and I'd hope you don't sleep with your ear against the tank anyway.
It'll come with a carbon pack; keep it in case you need to medicate; otherwise do not put that in your filter that'll extract all nutrition the plants will need to thrive.
Don't just go out and buy now; see if you can find deals, stuff on sale at your pet store around you etc, even if you only safe a few bucks here & there in the end you may safe $10 and that'll make for few plants already!