You could consider using open hardware monitor from http://openhardwaremonitor.org/
here's a screenshot of the monitor on my desktop as I have customized it. It shows voltages, temperatures, CPU and GPU loads, HDD temperature, and other things.
It's customizable, as you can name each component yourself and choose what things get shown in the gadget overlay. Furthermore, you do not need to have the vista/win7 gadgets installed to use this gadget overlay, even though it functions like a gadget! (It uses less memory too.)
The gadget is to the right desktop in the screenshot and the full program list is on the left desktop.
(You might have to right click and open in a new tab for values in the screenshot to be legible.)
I tried out the gadgets that you are using and they just didn't work well for me either. They displayed incorrect values, lacked customization, gave me useless information that I didn't want, like taking up space with logos or giant font names of products, and I needed 2 or 3 gadgets open to monitor everything I wanted to monitor.
That's what led me to this minimalistic and customizable overlay that I'm using now.
Edited by shad0wfax - 2/2/12 at 11:02am