I don't know of any single 'breakbeat' producers anymore. I think producers make a track here and there, with popular breaks. The art of breakbeat/scratching is a pretty niche market these days.
Edit : At glance I caught the name Stanton Warriors. They don't exclusively produce breakbeat tracks, but that is a huge focus of their production. Check out some of Evil Nine's older tunes, and Adam Freeland. Again, not exclusively breaks, but they dabble a bit more than others.