You might want to take a good look at the Kaman Kmax design, which is a production version of the intermeshing, side-by-side rotor concept. There are other factors to take into account including aircraft weight, profile, etc., but to my knowledge the Kmax is the most efficient fuel burned/weight lifted and horsepower-to-lifted weight rotorcraft out there, due in large part to its efficient large chord, slow moving blade system. It is extremely quiet for its size and and the rotorwash is somewhat self canceling and minimal for an aircraft that will lift 3 tons. In short, it has many of the features you are looking at (although not the fast forward airspeed - it was built for lifting).