Lots of choice.
Bling Chris king, though personally whilst I have a few on builds, I think they are expensive for what they are. They last ages as bearings are great, but you can't replace the bearings and the rubber ring inside the top race eats through steerer tubes unless you get the modern compression race. Plus the first thing you'll want to do is cut the crown race so it's easier to fit and remove.
You can't go wrong with hope. Well made, bearings can be replaced, though they last ages so you may never need to.
Cane creek were good bitd, I think s-8 were bomb proof. Modern forty versions are really good value too imho.
FSA orbit were also decent.
I'm sure there are many others.
Assumed as you have a nice frame and fsx you'd want a posh headset to go with them.