Travel agents in Berlin, recommendations

I need to get to Florence airport in the beginning, middle of may. Does anyone know a good travel agent that speaks English in or around Prenzlauer berg? Or whatever, ANYWHERE in Berlin? I'm desperate- it's like 250 euros for the train, i need some advice...

I just know Sta Travel. But I don't know, how good they are, but I guess everywhere at places where you can find a lot of tourists, people should be able to speak English.

Maybe also try: http://www.billigflieger.de/ for cheap flights.