Recommondations for Backup Solution

at my company, we have six servers, one that runs exchange, and have outgrown our backup solution. Currently we are using windows backup. What would be the easiest way to move to some form of centralized backup (i dont really want to use tapes). I want to be able to backup all of the servers, and would love to be able to set one set of backups and forget it. Would i use a NAS, server? Please, any recommendations for software and hardware, please.