What monitor should I buy? (27 or 32 inches? HDR? GeForce G-SYNC)

I have similar specs and originally purchased a 1440p 32". Then, saw the sim running at true 4k and there was no turning back for me. Just amazing even at 30-40 FPS.

Also, I tend to keep a monitor longer than other components so I was willing to accept lesser performance at 4k knowing that I will likely upgrade my graphics card before the monitor.