Firewalls - Need your input

Good afternoon/evening,

I am currently looking at multiple Firewalls for the district I work for (K-12 education) and was wanting some input from you guys! Basically looking to see what your experience is using or what you have sold to a school/business similar to my size and I am looking for pros and cons of each. We currently have a content filter (iBoss physical appliance) but if the Firewall can be granular enough to take its spot that is a plus. It would have to support offsite filtering somehow if that is the case. I have heard it being done with a Palo Alto but have not seen how granular it gets.

These are the current Firewalls that are being spec'd for us by the companies engineer. This would be for a small 5A school with 5-6,000 users. Basically, I just want to hear your input on what firewall you are using and why/how has it been since you owned it.
Currently, have 2 ISPs both are providing 1Gbps each. We would like to future proof for 10Gbps even tho the max we will ever use will be 2Gbps. Also only have about 5-10 VPN users total. We are also an iPad school 1:1.

• Barracuda F900 (I like barracuda but have not heard of a school using it)
• Fortinet 1100E (Heard several schools use Fortinet, but no experience with it)
• SonicWall 6650 (Heard some schools using it, but no experience with it)
• Watchguard M5600 (Can't find a K-12 school using it, I liked the stats/interface but very little K12 programs using it)
• Palo Alto (Has not been spec'd this but was looking at 5220 but also very pricey)