Most modern VFD's have terminal blocks available with integral power enabling you to wire pots, stop/start/ and speed step control in remote locations. Also, these drives will have the built-in PID tuning necessary to automatically control more critical processes, such as controlling recirc during sparging. A third benefit is that these same drives will have built in comm ports(RS232/RS485/MODBUS) with the option of adding ethernet/devicenet/etc. control options so you can use HMI's/digital readouts/network to pc- the sky's the limit.
That being said, Allen Bradley Powerflex series is a nice albeit expensive option for a small brewery. Since it is not a very complex operation, go to http://automationdirect.com and you'll pay half the price and get the same result.Plus, if you order the drives today, chances are they will be to you in a day or two.