If you want a combined one for under $200, I heard the Milwaukee SM802 is the best.

That being said, I talked to the company that makes the meters Image Reaper told you about. They said that a combined probe is not a good idea, further built-in temperature is important because the meter should compensate for the actual temperature to give you a reading that is compatible with the nutrient guide (which is based upon ppm @ 25C).

Good luck.