15 R3 Card for Graphics Amplifier?

I have a 15 R3 with i7 6700k at 2.6 ghz and a GTX 1060. I'm just getting into VR with an Oculus Rift S. I have a chance to buy a rarely used graphics amplifier from a friend. Thinking of tying to see what kind of future proofing I can do with my current laptop, how good of a GPU can I use in a graphics amplifier without the GPU bottlenecking or overheating my CPU? I assume a 1080 would be doable? How about some of the newer, higher performance GPU's?

Thanks in advance for any help. I've done a bone of searching but can't find any info specific to my CPU and laptop.