Found the brush pens and paper I was looking for at Daiso Japan here. Got the last of two different kana notebooks they had in stock.
They’ve got an awesome selection! Possibly even better than what I’d seen on Amazon recently. The clerk said their Alhambra location was even bigger, so I’ll have to go there soon.
The Pentel Arts Pocket Brush Pen was by far the best pen I tested today, but at over $20, it was on the expensive side and probably wouldn’t do as well for me at present with my mediocre skills at the moment. I’ll circle back around to it when I’ve practiced my kana a little longer.
I ended up buying a couple pens and two notebooks.