Just bought a small cabin on the St. Lawrence River and we are putting in a dock. Builder creates great steel mainframes drilled 6' into the rock, and it will be 100 ft long. He specs it with 2X8 pressure treated decking but he is willing to use other wood (if I am willing to pay for it). The lumber dealer recommends ipe or cumuru and I like the looks of tigerwood. Does anyone have experience with any of these to make recommendations?