Dell U3818DW (https://www.amazon.com/Dell-Screen-LED-Lit-Monitor-U3818DW/dp/B073FHWTPL?th=1). The Amazon reviews match my experience, specifically the one titled "Great for spreadsheets and coding, not great for multimedia". I'm a coder and this is great for me. Not sure what gaming performance is like.

As for having one big, ultra-wide screen vs two normal screens, no question: one big ultra-wide is better. Eliminating that gap between the screens makes a huge difference.