I've got a fifteen year old Giant road bike and would like to get new wheels. I've got 700x25tires on the original wheels now and a 7sp. cassette, but since it's so old I'm not sure what size wheels I need with all the sizes available these days. I would like to get some that are lighter (everything now is probably lighter) that are also strong. I'm not hard on wheels, but I'm on the heavy side (6'4", 210lbs.). I don't want to spend a lot considering the age of the bike, but will I need to buy and new cassette and rd as well? Any help would be much appreciated. Thanks!