Depends on what games you play. I get about 300fps on csgo max settings across all maps in 1080p, and i always get above 100 fps in some higher end games (high to ultra settings) like ark survival evolved and rainbow 6 seige, both in 1080p. Btw these results are all on a clock speed of 1759mhz, because I only overclock for benchmarks and for when i need more fps for shaders in minecraft
By partner cards, he means the other companies that produce the cards like evga, msi, zotac, pny etc.
To answer your other question, it depends on your setup. If you wanna run 4k vr high settings (or whatever combination of those) go for the 1080. If you just wanna get good fps at 1080 or 1440 go for the 1070.