There are two brands that my running friends and I recommend: Bob and Jogging Stroller.
I personally have a Bob Ironman (don't let the name fool you). I love it!
Things to look for and consider:
1. Where are you going to be using the stoller? Paved roads? Trails? The bigger the wheel, the smoother the ride for the child. One exception: the Bob strollers have suspension that most others don't, so their wheel sizes tend to be a tad smaller.
2. How much are you going to use the stroller? The more you plan to use it, the more I encourage you to spend a little more and get a higher end stroller.
3. Sun shades are important in the south. Make sure whatever you choose had adequate coverage.
4. A reclining seat is more important than you think! :)
5. Will you need to transport the stroller? What kind of car do you have? Will the stroller fit in it? Without taking the wheels off? (I hate dealing with taking the wheels off, so being able to get it in the car with the wheels on was very important to me.) How heavy is the stroller?
REI has the Bob strollers; they had a 20% off coupon in last Sunday's paper.
A good reference site: http://joggingstrollers.com/