I'm leaning towards the LG 34UC89G-B 34-Inch 21:9 Curved IPS monitor with G-SYNC, which is currently available for $499 with free shipping.
Have you considered taking the plunge into VR? At that price, and black Friday coming up you can get a good deal on one. Trust me when I say once you play a flight sim in VR, You'll want to store your monitor back inside its box. I mean like a full 2 hour flight in VR is amazing.