Several years ago I bought a Columbus Minimal 1" threadless all-carbon fork. Beautiful fork, lightweight, not cheap, but well within the normal price range of a high quality fork.

If you currently have a threaded set up, you can convert to a threadless steerer with a new headset - and decent headsets, say a basic Cane Creek, aren't really expensive.

If you want a CF fork with a threaded steer tube, look at Wound Up. Not cheap, not very light, but good reputation and I think they have what you need.