Get Plastic one only and get a quality one in it. Cheap one will bug you all the time with millimeter gaps and differences.
Get Assurance from shopkeeper that kit will fit exact shape and cuts of car else commodity will be returnable.
Fiber ones ruin your car's body at the time of fitting and usually do not get paint finish that plastic ones achieve. Once i saw sublime mark x getting holes drilled in foot side boards for fiber kit and was like :o