This article on radiation shielding lists various materials and their ability to reduce radiation from lead to steel even to lumber. Though lead would make for great shielding, with its density and current launch prices per pound it would be extremely expensive. The best option for vessel would either be using a lot of lightweight material such as aluminum or to process these metals for shielding either through asteroid mining or even from the lunar surface. (I hope that I answered your question).
I think that investment in these technologies is essential not just to reduce dependence on oil but also for greater sustainability globally. I think coupled with this there needs be a greater drive for recycling plastics and a reduction in the use of coal for power. (Thank you for your question).