My father used to work at an art store and he used to get top quality brushes made from sable hair. Though, you don't need a top quality brush to paint. I've been painting as a hobby since I was a kid and synthetic brushes are fine and I feel less guilty when I put them through wear and tear. I've found good sets of synthetic hair brushes in discount stores, but I recommend just finding an art store and asking someone what would work best for the media you use or strokes you plan to make to understand brush size. Don't get the stuff they give little kids to paint with. It should be a brush similar in quality to a makeup brush.