I believe that Schwalbe S-One are available as 650B
They are very fast and I've found them to be reliable (in 700c version on the vorsprung machine)
They are 30mm wide and have a light tread
The G-One seems to be the same thing but wider (35mm) and with more tread
They are available in 650b but for some reason seem to be out of stock everywhere.
I was running G-ones recently (tubed) too, 700 cc in 30mm.
I know you need a tight fit for tubeless, but holy crap they are hard to seat (140 psi eventually popped them on)
Lovely fast tyre, good grip, but I have switched on the grounds that I'm not confident I could get em back on out in the field.
They were hard to track down in 700 cc too when sourcing.
Probably just bad luck but the front tyre picked up a big cut and should really get the big heave ho.
Switched to roubaix as an alternative.