Reommendation for a network setup to aggregate and load balance 5 ADSL lines

We have 5 ADSL lines* in our office; each line has a separate router+wifi hotspot. We want to find an excellent way to Merge those 5 ADSL lines to get the benefit of the speed combined and balance the load too.
Some people recommended pfSense (Software), some people recommended Sophos (Software), and some other people recommended Sophos (Hardware).
Here are our basic requirements:
- Aggregate the 5 ADSL lines.
- Load balance the 5 ADSL lines.
- Monitor the traffic for each device.
- Limit the traffic for specific users/devices.
- Limit the traffic for particular websites (increase for Skype, throttle for Youtube).
- Up to 150 connected devices.
- Two WiFi hotspots (75 devices each) with the same SSID.
*Why 5 ADSL lines? the internet connectivity sucks in our city!