Cup style is more preferred. With the impeller models (like the Kestrels), you have to get it pointed directly into the wind stream otherwise it won't get a good reading. Kestrels are still good though, especially if you want to get one that you can carry around your neck or put in your pocket. Several models measure temperature and dewpoint, also.
For your use, I would recommend the InSpeed handheld model. It's cheap, works really well, and it's easy to perform maintenance. I can't remember the price, but I know it's well under $100. I've had one for several years and love it. I have one of the mag mount models for chasing also.
