The only thing I can add is that you'll have to learn from experience. I bought a badger, boar, and synthetic my first year. All different in knot size and loft. After a years use I found that I prefer boar brushes. The boar, however, had a large knot with a tall loft. As someone who face lathers and only does a two pass shave, this brush was not ideal. It ate up a lot of soap and was too floppy. I looked around and found the Semogue 1438. It is the perfect brush for me, and it's all I've used since I bought it.
My advice is to take note of what you like and dislike about your current brushes. Then, take a look around and find one that fits your needs.
My advice is to take note of what you like and dislike about your current brushes. Then, take a look around and find one that fits your needs.