Its got almost 190K on it and has always ran a little warm especially first thing. But noticed the other day it got almost to the end of the range on the temperature gauge so I grabbed a thermostat and replaced that. Drove it to work Friday morning fine then on way home it got almost to the H and I'm trying to figure out if the next step is a water pump or radiator?

I assume that you have a 2.2L since the 2.4L has the water pump buried and the thermostat buried below the water pump. I have the 2.4L so I can' speak from experience, but the following thread suggests some possible fixes (including the heater core and radiator fan).
http://www.automotiveforums.com/t628574-discuss97_cavalier_2_2_overheating.html