I think you have made a good choice to go with a Heritage speaker. If I'm reading this right, the length of your room is ~40'? If so, that's a pretty big room for the Fortes. What is the width? I know you said the CW was too wide, but it can be as close to the wall as the Forte and still sound pretty good. It will certainly fill that big space much better. But I'll go you one better. If a CW will fit, so will a lascala.
I'm a little curious what you were powering the Infinity speakers with? Those aren't very friendly to low powered amps.
Whatever you decide, going from 88db sensitivity speakers to 99db is going to be quite a treat.