You're better off with regular thermal paste. Since you're inquiring about Thermal Grizzly, you can use anything they have or look at Noctua's NH-H1 or H2 or Arctic's MX-5. Following that, you could go one step further by changing out the thermal pads for something higher in quality, like that made by Fujipoly. You will however have to make sure the thickness of the pads are right, having a mere 0.5mm gap in mounting surfaces for any cooling solution can be the difference between good thermals and a dead component. You will need a small ruler or scale to help you understand the thickness(and length) of the pads.