Ruckus 7731 and P300

Hello everyone ,
I want to connect 3 School buildings by using wireless bridge (7731 OR P300) the distance between one and another about 100m ,also I want to use APs in the Schools’ Building to connect the classes wirelessly (could you help me to choose the appropriate APs I can use ? , one of the building is very old and has a very strong building ) , Do I need Controller for APs and Flex Master for wireless bridge , Also which one of the wireless bridge I can use ? …
Regards ,