karma to you for planning on using a QT !! Excellent!
I have never liked the Whisper filters because their media is so thin. I prefer an Aquaclear hang on powerfilter because it has a much larger media area along with good water flow.
The Aquaclear allows for three layers of your choice of media. Inside my Aquaclear hanging on my QT are three thick sponges. These sponges are large and thick allowing for lots of surface area for the nitrifying bacteria to colonize. Once medication is complete, I remove the last sponge and replace with carbon or a polyfilter to clean the water.
Depending on the type of cover over your tank, you may want to forego using an air driven sponge filter because of the huge amount of saltcreep they create where the bubbles pop.
My vote is for an aquaclear hang on powerfilter
Plan on cycling your QT thoroughly before adding any fish! Check out the link in my sig "Lifesaving QT" for how I cycled and set up mine.