Setting up Firewall and Webfilter on small Network

Hi all,

I have a small network with 50 people with 3 equipment: HP Router 7102dl , HP DL180 G6 with Windows SBS 2008, HP Procurve 2650-48P Switch.
However, client has been abusing visiting unsolicited websites that I would like to block and at the same time protect network from hackers.

I am looking to purchase Cisco ASA 5500 or FortiGate 100D equipment.

Which one would you recommend to me for the type of my network described above???
I am looking the one that is easy to setup and to configure…

Thanks