An aluminum frame is more than strong enough, I am a big guy 6'4'' and hover between 300 and 350# usually (I need to keep it closer to that 300!) but my point is that I ride aluminum bikes and have not had an issue yet.
I have trek Xcaliber and LOVE the frame geometry and I think it is because I too have a long torso and short legs and the GF bikes seem to have a longer top tube so my short legs and long torso/arms seem to like the way they fit. Have you looked at the Trek DS Models? they share the same long top tube as the Xcal and similar models and sound like what you are looking for going off of your description besides being more mountain than road 48/36/26 for the 8.4 DS triple vs a 50/34 double on the bicycle that you linked, The DS model may be something to consider.
I also agree with the posters that say if it ain't broke don't fix it with the wheels, but I would think that most shops would be willing to give you credit for the wheelset trade off of the new bike if you were upgrading the wheels through them, thats how the LBS I use works anyways.