I live in Columbia where Mizzou is located. It is NOT country side. It is country around the city, but the city itself has everything you need (food, shopping, culture, sports, parks, etc). There is a lot of diversity in Columbia, including a lot of traveling physicians at the Hospital and a lot of foreign students attending Mizzou. There are about 100k people.
Also, if you want a bigger city, Saint Louis (2.8 million people) and Kansas City (2 million people) are only 2 hours away. It is also very cheap to live here compared to your other choices, so you would save $$.
I'd pick Mizzou! And I won't blame you for missiles if you don't blame me for George Bush :-)