There are several options in the art store and these are some of my favorite that I use for my paintings and workshops.
Paper:
100% cotton cold pressed, 300g watercolor paper, I like arches, bao hong and fabriano artistico best
Brushes:
Black silver brushes round shape, size 16, 6,
Black silver brushes flat shape, size 1"
Princeton heritage brush round size 12 and 8
Princeton Snap brush round size 16
Paint: Holbein professional paints and Sennilier professional paint
You can get the list of other brands I have tried in my free resource.