Am Changeing my brake rotors and pads all the way around. I like to use orielys auto for my parts. According to them the oem pads were ceramic on back and semi metallic on front. He said semi metallic has better stopping ability compared to ceramic. Should I stick with those up front or how would ceramic be? Also I need to replace my pinion seal, they have one for 5.00 and one for 22.00. What could be the difference?