There's nothing difficult about switching wheels, bars, stem, and saddle. Even if I wasn't concerned about weight I would switch the saddle and bars/stem for fit and comfort. As far as wheels go, Zipp isn't the only brand out there. Yes, going tubular is the only way to go super duper light, but you can get under 1300 grams with clinchers. Again, that's 470 grams saved over stock wheels. That's 1 pound. Even if I accept your 16.5lb weight, there are only about 230 grams to go with the saddle, stem, and bars.