Thermal pad replacement question

[cardsfanbj]

I recently bought a Gigabyte GTX 1070 Windforce off eBay and I was going to replace the thermal paste for it, but when I went to open it up, the thermal pads are falling apart. 

I am brand new to this, and I have no idea about ordering new ones. Any help would be greatly appreciated.

Since I ordered it on eBay, it came with nothing else. No manual or other info.

Things I know I don't know:

• thickness of the pads (or where to find that info)
• reputable brands of pads and where's the best place to buy

[cardsfanbj]

[cardsfanbj]

With help from Micro Center, we figured out it's .5mm for most of them, and the far right (top)/far left (bottom pic) are 1.5mm