Bastard keyboards is selling some of the coolest contoured keyboards out there. Furthermore, Quentin who runs the business seems like a great bloke. On top of that, every keyboard is open sourced as far as I know. Cyboard does also make contoured keyboards tailored to your own hands. I’ve heard great things about him as well.
If you’re interested in something different, one really promising keyboard project just launched: Svalboard. It’s a customizable and in many ways modernized version of the Datahand (and therefore not a curved keyboard, but it still retains all of the benefits of a curved keyboard). I just can’t stop to think about that one. It is however way out of my budget.