Nice looking setup. 46g will give you more options for sure. It's not too tiny, nor too big. Easy to manage for water changes, even if you have to do the bucket toss.
FWIW, with my Sunsun 302, I run the thick blue sponges in the bottom two trays, then a bunch of different bio media in the top. Plastic balls, ceramic rings and plastic pot scrubbers. I found if the floss pads are used in the lower, dirtier trays, they plug-up too quickly and hinder the flow through the filter.