Carbon gives strength and kevlar material provides flexibility. It will save you a lot of time in case of potential damage during competition weekend. Carbon/Kevlar parts can hold up several contacts and hits, without need of replacing them. And at the end it will save you decent amount of money.
High performance polycarbonate [sapphire coated] window kit will save your money and time. Sapphire coating will protect glass from scratches and it will stay clear and visible even after 5 years of usage. Approximately 50% weight saving compared to glass. Thickness - 3mm.