I use Everest Ultimate Engineers Edition or something, works really well, does whatever temps you want for anything, also monitors vcore etc etc.
for GPU you can watch:
GPU
GPU Diode
GPU Memory
GPU Ambient
all diff temps, lol, i just have the main GPU temp cause I got no idea what the others are, haha, but yeah, anything you wanna watch it just pops up in the system tray icons just as numbers with a coloured background depending on what you are watching.
It is real good
Sydz