What kind of coat do I need?

I’m in the midwest, where winter temperatures range from about -5 to maybe 40 on a good day. I desperately need to buy a new coat – the one I have is a cheap polyester/wool blend that’s thin and definitely does not do the job. But I am totally lost as to what kind of coat to buy. (I’m used to warmer temperatures.)

Should I just go with a good quality wool coat? They seem the most stylish. Or is a faux shearling warmer? Maybe a puffer? I honestly don’t know which one would be warmest and I would preferably like one that is around knee length but doesn’t make me look like a huge blob. And I’d like to spend less than $100.

Suggestions?