Unsprung Weight: Wheels

I am about to put my notch back on the road and i am currently deciding what tires to buy. I have all 98 cobra suspension/brake/wheels on the car now which work awesome, but this stuff is way heavy. I am looking to shave off a few lbs of unsprung weight and got to thinking about the wheels. The 98 cobra wheels are really heavy, but i need at least a 17" wheel to clear the brakes. I was thinking about getting a set of 03 cobra wheels because they are lighter ( and look really good). What do you guys think? does anyone know how much all of the different wheels weigh? Do you think i would notice a difference between wheels or am i just trying to hard to rationalize spending $500+ on a new set of rims?