Well for me I would go for Urethane because if itz durability and its overall appearance after u paint. By the way itz easier to paint urethane and itz easy to work with because it is flexiable and light. But the style is limited because about 95% of body kits out there is made fo fiberglass and the cost os cheaper on fiberglass but after awhile the paint wont look as good and one rock chip on the bumper would make it look bad. Wings West, Tsunami, Kaminari, are some of the brands out there that makes urethane kits. Anyways thats what I recommend, best of luck to ya finding the right kit for your car!!!