Taken apart and now overtaken by events.
I am not aware of any differences regarding the use of thermal pads in a GPU being configured into some higher level of performance.
Overall, product quality is the key concern with respect to both thermal paste and thermal pads.
However, full disclosure, that is all going somewhat out of my comfort zones.
I can suggest that you google "Do gpu's need special thermal pads or paste for overclocking" or other similiar words and phrases to find out more about the topic.
In the meantime, someone else may post additional comments, ideas, and specific suggestions.