I use paint from many suppliers; Sherwin Williams, Diamond Vogel (Ruffes), Kwal-Howell (Pro Build), Benjamin Moore, Behr (Home Depot) & exterior stains from Sikkens (Mesa Color), Cabots, Messmers, and others. Prices all vary depending on the sheen & manufacturer. Some products cover better than others, some seem to “stick” better on the roller, but generally, it takes two coats to get a perfect finish. If you have a preference for a specific brand that’s fine. If not, I generally use Sherwin Williams or Diamond Vogel from Ruffes. Both have zero VOC paints which are nice to use but tend to cost more. It’s all up to you.