We are looking at moving away from the SWGfL as our ISP. Ideally I think we will go for a managed (DNS, domains etc) 100/100MB line supplied via Virgin. We no longer use any of the SWGfL services as we host our own email and web servers as well as provide our own filtering system via Bloxx. So we need an easy to use firewall that can be configured by the Network Team to open ports, filter traffic and traffic shape etc. We had been looking at Smoothwall options however this bring us to a problem with their licensing...
Currently we have around 700 PC's and laptops that could possibly be in use at any one time. We have recently also allowed BYOD for the 6th form we enables them to add up to 2 of their own devices per student. In the future this is going to be increased by allowing years 7 to 11 the same features. This means that our possible live devices could be huge and there we need to purchase a system that is not licensed per device but rather a set amount not matter how many devices.
Watchguard are pretty good - and depending on if you run VMware you can have a virtual appliance.