Just trying to say you weighing 130 pounds is already a significant advantage... I mean anything you remove from the Z will be very very small. Like I said below, the most worth it mods to do weight reduction is the lightweight flywheel, specialty Z High-5 Puck that is half the weight of the stock clutch, and underdrive pulleys. Just guessing though, your only looking at 20-30 pounds from all three total.
I'm a swimmer as well ( I love the butterfly stroke), but I'm a big swimmer and weigh 230 lbs.