I've got an important tournament game coming up, and I will be playing Black. I will play the Scandinavian if White plays 1.e4, but I won't be able to unbalance the game properly after 1.d4, except if I play the Benoni(Old Benoni cuts out all transpositions). I don't like the Czech Benoni, where the break f7-f5 weakens my kingside.
Is there a line for Black in the Benoni that is tactical, sound, and stops White from getting a large center?