I used the Brazilian Hardwood IPE. It was comparable in cost to mahogany or trex. You can find places that will ship it to your home for a reasonable cost. The wood is extremely hard and requires no maintenance. It starts dark brown, and if you decide not to treat it, it fades to a nice grey. It's been used on several boardwalks around the US because of it's resistance to water and insects. It's virtually indesctructable. When choosing a material, I wanted something that didn't splinter (like Pressure Treated) and my neighbor has installed a composite decking, but found that mildew can form on it if it's not scrubbed regularly. You'll need a good skil saw with a high quality blade. There are some great fasteners out there like the ipe clip, which allow you to install the decking with no screws showing. Check it out, it's really nice stuff.