Help With Stereo

I have a 2002 Honda Accord EX Sedan and I wanted to change the system in the car. My friend and I were debating whether to get the receiver or the speakers first. We were afraid that by getting a new receiver it'd blow out the stock speakers. We also were afraid that the stock receiver wouldn't power a set of new speakers. I was trying to look for the specs on the stock system but was unable to find it. Does anyone know what it might be? And would you guys have any recommendation to a receiver and speakers. I was only planning on getting one at a time. Also, would you guys recommend getting a sub as well or will new speakers provide enough bass? Thanks for your help.