Purdy...I have used them for interior wall painting for years, and recently added their natural bristle brushes to my arsenal...I cut some of Steve's fairy patterns for the garden, and used the Purdy natural bristle brushes to apply Cabot exterior stains (all the outdoor stuff gets treated with this stuff)...I normally use cedar or cypress for the outdoor stuff.
As for interior stuff, I don't paint anything...As much as possible, I try to select woods based on their natural tones for a particular project...If I need to add color, I stain using dye stains...Paint and "regular" stains are pigment colorings that remain on the surface of the wood, which have a tendency to hide the grain...Dye stains, on the other hand, penetrate the wood and allow the wood grain to show through.