25 lbs including rack and panniers is pretty light, it would be a little silly to install a rack and front panniers weighting several pounds just to redistribute that load.

Another option would be a big saddlebag like the Rivendell Baggins bags or the Carradice Nelson bags, with a handlebar bag. People who use these claim they the load closer to the center of the bike. Jobst Brandt, author of an excellent text on wheelbuilding called "The Bicycle Wheel", has done many tours through the Alps with this kind of arrangement.