Fitdiva

Hello. I own a 1999 RX 300. Paid $19,500. Have had the car for 2 years. It had 50k miles when I purchased now it has 112k miles. Problems: 1. Brakes. I need rotors. Is this a common Lexus problem. Squeaky brakes but every place that I took it said I did not need shoes or pads. Now I need rotors? How much and where can I purchase them. I have a mechanic to put them on for me. 2. Auto Fuel Ratio Sensor. Check engine light came on and I took it to dealer. They said I need this part. Can I get it from somewhere else and find a good mechanic to install it for me. How much should it cost? 3. What type of gas is best? I've been using regular unleaded. Should I upgrade? 4. Someone backed into me and broke the Lexus emblem (the L) on the front. Where can I get one? Thank you.