Getting a truck lighter?

[Roper]

Well im getting closer to finishing my truck. All thats left is the body.Was wondering what options I have? Example less weight mean faster and better fuel mileage. Was wondering about figerglass or alunimin body panels. There is an outfit in Florida that makes fiberglass complete race bodys for my 81 Chev 4 by4 that weigh absolutely nothing. Problem is they wont ship, you have to go there and pick it up yourself or arrange your own trucking and assume all the risks. There body parts are not direct bolt on either.
Does anybody closer to AB make fiberglass body parts>?
Alunimin would be perfect. Does anybody make alunimin body panels that are half way affordable?
Any of you have other ideas on saving weight? Example im getting rid of my back bumper and probable going to replace it with a tube bumper. The bumper I have just fills up with mud and weighs God only knows how much.