Specializing in painting ink and landscape paintings, green landscapes, it is best to send soft and luxurious pens. This kind of brush is mainly used for dipping, sweeping and putting. It needs water in the stomach and has a large amount of coloring. You can choose a medium size.
Specializing in meticulous painting and so on, you'd better send a hard one or pick one from Gou Xianbi. This kind of brush requires uniformity, and the water content should not be too large. You can choose a better Gou Xianbi.
Chinese painting is inseparable from inscriptions and calligraphy. If you are a novice, you'd better buy a hard brush or a double brush. If you have deep skills, you can buy a soft one. But it also depends on your personal preferences and the way you learn calligraphy. Different styles also need different brushes to play to the extreme.
Similarly, friends will be happy to see you give a pen, no matter what it is. Friendship is not a ceremony.