The brush I use in class is one of the above, size 5 I think. Its a lovely soft brush and has lots of spring (which helps you create super shapes)
If you are looking to upgrade your watercolour equipment or maybe starting out with one of the short courses read on as I have two very reasonable recommendations for new brushes and paper.
Brushes and paper are key to watercolour painting, more so than any other media. Getting the right equipment especially if you are a beginner helps you enormously.
The brush I use for washes - mop from Rosemary and Co, a fantastic company that make all their own brushes
same mop synthetic https://www.rosemaryandco.com/pointed-golden-synthetic
general brushes under £10 https://www.rosemaryandco.com/watercolour-brushes?price=-10
I have also sourced some paper from Jacksons Art,
Jacksons: Saunders Waterford watercolour cut paper packs https://www.jacksonsart.com/saunders-waterford-cut-watercolour-paper-packs
Let me know what you buy and what you think