To repeat my private message 
I spent a ton of time researching FF's and went with the Petroff Mini FF, available in the US from Visual Products.
Extremely flexible and well-built at that price point, and that includes an easily reversible gearbox.
One of the features people overlook is the gearbox ratio; some units expand it, some contract it. The Petroff has a mild expansion ratio of 1.33:1 so it favors SLR lenses with a short focus throw. Even then, it takes Zacuto drive gears so you can change the ratio within seconds.
I spent a ton of time researching FF's and went with the Petroff Mini FF, available in the US from Visual Products.
Extremely flexible and well-built at that price point, and that includes an easily reversible gearbox.
One of the features people overlook is the gearbox ratio; some units expand it, some contract it. The Petroff has a mild expansion ratio of 1.33:1 so it favors SLR lenses with a short focus throw. Even then, it takes Zacuto drive gears so you can change the ratio within seconds.