It looks pretty legit I was planning on getting the downpipe and catback from them but i havent read anything about them(links at the end). im pretty new to this (just got my sunfire gt last month) and am hoping someone with experience could weigh in. Also would it be better to go with 2.25 or 2.5 piping? (I dont plan on doing a whole lot of mods and definitely will not be going turbo)

links: downpipe , catback