It's the bios that must match.
Overclocked cards should clock back, though i have read of recent compatibility issues. (can't remember where i read this though)
You can grab a different brand at stock clocks and that should be fine.
Corsair 750D :: 750W DPS-G:: Asus x370 PRO :: R7 1800X ::16gb DDR4 :: GTX 1070::525gb SSD::Coolermaster 240MM AIO::