Perhaps my English grammar is poor but I would be far more likely to say 'Who here do we need?'
It seems more emphatic on the 'here'.
I would be far more likely to say "Whom do we need here?" Here feels odd in the middle of the sentence. Also your example would also use 'whom', not who, as it is the object of the verb, need.
From the English side, "in" adds an element of location that is not present in the Czech sentence. It restricts "here" to someplace indoors, while you could just as well use this question outdoors.