Driver Replacement Tip

I just bought my first car, 1996 Mustang. It needs a little bit of work. I need some advice about where to find some replacement parts, for as low of a price as possible. There's a missing driver side mirror, and some missing buttons on the steering wheel. I have some pictures below. I am also looking into buying a new muffler, exhaust tips, or something of that nature, to make the car sound better. Any info on that, and where to buy, would also be helpful :]

http://i231.photobucket.com/albums/ee190/ktswnsn/securedownload-1.jpg

Thanks!
My area code is 53170.