Temp monitoring

Everest from Lavalyst is a good option, you can choose between a lot of different monitoring from temps of different components.

I have Everest Ultimate, costs money, but is really great. I think, Everest Home is free, but don't know if it has the option to show monitoring in the task bar.

There are also a variety of different other programs that helps you monitor the temps..

For your gpu? ATItool should be fine.

You do have the option for Everest to show live monitoring of your choise on the task bar. So you don't have to open it and go to the sensor section in order to check the temps.

Rivatuner will display temps in the tray.
Why do you want the temps displayed in the taskbar?