This is a nicely balance system. Rotel and B&W compliment each other well. The Marantz and Tara Labs are smooth and not hard. Wouldn't change a thing, or you might open a can of worms ad start going backwards.
All you need to upgrade is your picture reproduction. Samsung 30" HDTV, Samsung 46" DLP, or Panasonic 42" Plasma EDTV are great values.